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Full text of "73 Magazine (October 1973)"

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October 1973 

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magazine 

for radio amateurs 



#157 OCTOBER 1973 



EDITORIAL STAFF 

Wayne Green W2WSD/1 
Keith Lamonica W7DXX/1 
RonSubkaWA9FPP/1 
Yvetre Grimes WA8ULU/1 

ASSOCIATES 

Gus Browning W4BPD 
Mike Frye WB8LBP 
BilJ Roisington K1CLL 
Dave Ingram K4TWJ 
Jim KyleKSJKX 
Harry Simpson A4SCF 
Bill Turner WA0ABI 

PRODUCTION 

Ruihmary Davis 

Karen Hebert 

Biff Mahoney 

Pen Mahoney 

John Miller 

Janet Ox ley 

Lynn PancieraFraser 

Philip Price 

Bill Suderman 

Bill Sundherg 

BUSINESS 

Knud E.M. Keller KV4GG/1 

CIRCULATION 

Barbara Block 
Jackie Garner 
Dorothy Gibson 

TRANSPORTATION 
Kurt Schmidt 
Jinx Town send 

PROPAGATION 
John Nelson 

DRAFTING 

T.M, Graham W8FKW 

Bill Moiello 

Waynp Peelei K4MVW 



FEATURES 

1 Table of Contents 

2 Never Say Die W2NSD/1 

4 Fantastic Code Tape Offer 

5 SSTV Scene 

6 Slow Scan Program Contest 

7 DX Footnotes 

7 Social Events 

8 Repeater Update 



8 Contest Announcements 
8 New Products 

10 QSL Contest 

1 1 Caveat Emptor 

1 1 1 Phase Lock 

112 Ad Index 
112 Propagation 



CONTENTS 

13 Converting the G.E. Pocket Mate . , , . WB4DBB 

Transform a pocket transceiver into a 

pocket transceiver! 
17 Frequency Measurement at Microwaves . . WA9VFG 

Be prepared for equipment with tiny knobs. 
21 2m Front End Using One IC K1CLL 

A high performance 6 transistor design. 
29 Instant Replay for your Tape Recorder W6FPO 

A tape recorder is a must for Slow Scan. 
31 2KW PEP Building-Block Linear W2EEY 

Module design leaves room for improvement. 
39 Yet Another Wattmeter . . K5CXN 

Did you build your first one yet? 
43 Meter Legerdemain WB2PAP 

Pull a rabbit out of a broken VOM. 
49 Europe's DX Repeater W2EEY 

Is 2m WTW a future possibility? 
57 Two Band Balanced Dipole W20ZH 

Another high -wire act for your back yard. 
61 A Digital "HI" Generator WA6JMM 

Even a Chevrolet can learn CW. 
67 Oscillating Ring Counter ...*... Weinstein 

October foolishness. 
69 Frequency Multiplication with Transistors ........ . K1CLL 

Bill Hoisington turns down his thumb at 

the standard circuits. 
77 Amateur Rules and Regulations, Part V FCC 

This month the watertight compartments 

of the Titanic are explained in detail. 



73 Magazine is published monthly by 73, Inc., Peterborough, New Hampshire 03458* 
Subscription rates are $6 for one year; in North America and LIS, Zip Code areas overseas, 
$7 per year elsewhere. Three years, $14, and $16 overseas. Second class postage paid at 
Peterborough NH 03458 and at additional mailing offices. Printed at Menasha, Wisconsin 
54942 U.S.A. Entire contents copyright 1973 by 73 Inc., Peterborough NH 03458. Phone: 
603-924-3873. Microfilm edition of 73 available from University Microfilms, Ann Arbor, MI 
48106. Magnetic tapes available from Science for the Blind t 332 Rock Hilt J?d. t Bala 
CynwydPA 19904. 



OCTOBER 1973 




MISQUOTED 

The editor of a small DX 
publication — a sort of newsletter for 
contest ops — took me to task for the 
July article on the repeater 
regulations. Normally I would ignore 
something like this, but the technique 
is all too familiar and I would like to 
point this out in case someone 
mentions the piece to you over the 
air 

In this editorial I was accused of 
holding that it is illegal to experiment 
with antennas which are to be used 
for repeaters — that it is illegal to 
operate a repeater on reduced power 
when necessary — that it is illegal to 
use the same station for auxiliary link 
and remote control and forbidden to 
have more than six control operators 
for a repeater. Not one of these things 
did I say in my article — not onel 

From thene the editor proudly goes 
on to disprove my statements. Big 
deal. What I did say is on pages 59-60 
of the July issue of 73 and has little 
resemblance to the statement by the 
editor. Obviously he was counting on 
his readers not reading my article - 
and he is probably right as 73 does 
not cover contest activity in depth 
and there probably is little overlap, 

Since many readers do not take the 
time to read through things like this 
carefully, and thus may be confused 
about the above points, let me point 
out that it is not in any way illegal to 
experiment with antennas — as long as 
you don't do it on your repeater* 
Your repeater antenna must be the 
one that the FCC has okayed for your 
repeater. If you are going to change it 
even for a short while, you should 
apply to the FCC for permission and 
include the horizontal and vertical 
patterns of the new antenna, unless it 
is an accepted commercial antenna, in 
which case you merely refer to it by 
its nomenclature. When you get the 
official word from the Commission to 
change, then you change- I realize that 
this sounds insane, but this is the way 
Walker wants it and the way HE reads 
HIS regulations — and this means that 
this is what we are stuck with for the 
time being. 

It is difficult to keep up with the 
ever changing interpretations of the 
rules. Walker was ad amen t at first that 
the control operator must have some 
system for keeping the repeater on the 



EDITORIAL BY WAYNE GREEN 

air with a pulse or something that 
would indicate that he was in active 
control. This seems to have been 
dropped - thank heavens. 

Walker has not relaxed much on his 
position on a maximum of six control 
operators. This is not in the FCC 
rules, it is just a Walkerule, but it still 
has caused quite a few repeater 
applications to be rejected; 
nevertheless. Walker does say that if 
there are serious extenuating 
circumstances that he might accept 
more than six control points. 

As far as operating the repeater 
with less than the power applied for 
on the license application, the Walker 
approach is that any changes in the 
parameters set up in the application 
must have official FCC sanction 
before being made. The repeater 
power obviously is one of these 
parameters and there is nothing in the 
rules about being able to operate with 
lower power with no notification. 
And Walkerules state that notification 
MUST be before the fact, not after, 
and that sanction must be received 
from the Commission before changes 
are made. 

These things are all idiotic and the 
sooner we are able to get rid of the 
paperwork garbage the better. In the 
meanwhile the less squabbling there is 
in the ranks the better. The editor 
who backs up the FCC to the hilt like 
that is no real friend of amateur radio. 

JOHNSON BLASTS FCC 

FCC Commissioner Johnson, whose 
term officially ended July first, but 
who is serving until Nixon finds a 
successor, lashed out at the 
Commission recently in an article in 
the Yale Law Journal. Johnson said 
the FCC is "manipulated daily by the 
industries it is supposed to regulate 
and by its staff." Certainly amateurs 
have seen that happening in recent 
months, with the deluge of new 
Walkerules and the 224 MHz CB band 
that seems to be wanted by only the 
Electronics Industry Association — 
the Washington lobby for the CB 
industry. Money talks. 

"As a result," Johnson continued, 
"the commissioners often make 
precedents which return to haunt 
them." Like the 27 MHz CB band, 
perhaps. 



NASA NIXES HT 

With a bonafide ham aboard the 
next to the last Sky lab trip, it seemed 
a natural to have him pack along a 
little hand unit for some two meter 
FM work. The space and weight were 
no problem — but the politics was* 

Owen W5LFL was already in the 
clean room a few days before 
departure when K3GKB managed to 
get a little four channel hand unit 
through to him via Owen's wife — 
only to have NASA officials turn 
thumbs down on the basis that they 
didn't want to have any possibility of 
anything being said from Skylab that 
they couldn't censor before release. 

Some amateurs have gotten 
reprimands from NASA for tuning in 
the down link and giving the 
information to news media or letting 
it go through local radio stations. 
NASA wants complete control over 
everything coming from space. 

Pity. 

Imagine the pileups on 34/94! And 
52/521 Plus he had one 147 MHz 
channel set up for simplex that Clegg 
users would be able to jump on right 
away. 

Pity. 

REPORTS NEEDED 

Though radio amateurs are 
intimately involved in virtually every 
serious disaster, not one in a hundred 
are written up and sent in for us to 
use in the newspages or in our letters 
to congress, Please give us the news to 
use for these valuable services. 

Most ops who get involved in 
emergency work put their all into it 
and then figure that once the job is 
done the job is done. There is still a 
responsibility to help amateur radio 
by making known what has happened 
so you can reconstruct the story later 
and know that you have it straight. 

While only 73 and OST are into this 
type of news, I can assure you that 
both of these magazines will 
appreciate knowing what has 
happened. 73 gives you the extra 
advantage of knowing that your story 
has a good chance of being told to 
congress — and might get into the 
Congressional Record. 

FCC HEARING 

Plans are well along for a public 
hearing before the FCC Commission- 
ers en banc on the matter of the FM 
repeater rules. The hearing seems to 
be coming as a response by the FCC 
to the 73 editorials and pressure to 
re-examine docket 18803. The en 
banc hearing was suggested by FCC 
Chairman Dean Burch in a phone call 
to 73. 

A position paper is in the works 
which will explain the problems with 
the new rules, why these rules present 



73 MAGAZINE 



CONSIDERABLY SPECIAL 

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OCTOBER 1973 



problems, and what amateurs re- 
commend be done to improve the 
rules. This paper will be provided lo 
the Commissioners and other interest- 
ed parties (Walker?) before the hear- 
ing. 

Representatives of many of the 
major repeater groups will participate 
in the hearing. Since time will be very 
limited, this will probably be kept 
down to perhaps a dozen at the most. 
Every effort will be made to have 
intelligent, well informed and erudite 
men to answer for all of us at the 
hearing. The last thing we need is 
some egomaniac taking the floor to 
create a bad impression and waste the 
whole hearing for us. > .and, as you 
may realize, amateur radio has more 
than its share of these critters. 

The ARRL was granted a hearing 
by the Commissioners on July 9th and 
the reports are that they created a 
favorable impression with their pre- 
sentation of the good aspects of ama- 
teur radio, Unfortunately they appar- 
ently did not get around to explaining 
why amateurs are so uptight with 
Walker about the new rules — so this 
job is still ahead of us. 

It is hoped that the result of this 
hearing will be a re-writing of the 
repeater regulations. There are many 
of them that are in bad need of 
elimination or serious change. Con- 
sidering the degree of self-regulation 
of amateur repeaters, it would seem 
beneficial to have all of the antenna 
restrictions removed, power limita- 
tions removed, crossband restrictions 
removed, control restrictions remov- 
ed, map coordinates and height calcu* 
lations removed, block diagram re- 
quirements removed, band limitations 
removed, power calculations and an- 
tenna pattern requirements removed, 
multiple repeater interconnection re- 
strictions removed - and things like 
that. 

Amateurs, based upon their fantas- 
tic record of achievement and service, 
deserve to be set free to experiment 
and develop in whatever way they 
desire. 

Once we are able to back Walker 
down on his Walkerules and Walker- 
interpretations, perhaps we can get to 
work on bringing other recent rulings 
into line — such as the third party 
traffic restrictions. The FCC handed 
out a notice of violation to an ama- 
teur in a drive-in theater who revealed 
the price of admission to someone on 
their way to the drive-in I This insanity 
has to stop too! The original rules 
prohibit pecuniary interest and per- 
haps that is where it should stop. If a 
chap in Bolivia wants to know where 
the devil his antenna rotor he ordered 
from an outfit in New York is, we 
should be able to call in for him and 
find out* The fact is that Ma Bell 



makes out just fine with most phone 
patches and darned few ham messages 
cut into any possible phone revenue* 
Ma is doing very well anyway, and her 
major problem is in keeping up with 
service, not trying to hog it. 

We'll try and bring a full report on 
the FCC hearing - hopefully with 
some good news on possible rule 
changes. 

Repeater councils that are interest* 
ed in helping support this hearing 
should immediately prepare a paper 
outlining the rules that should be 
changed - why they should be chang- 
ed and how they should be changed. 
Councils who have provided this paper 
have a right to send a representative to 
the hearing. Please send the paper to 
73 Magazine — and let us know who 
your representative might be and how 
to get in touch with him (or her?). 

In answer to the editors and ama- 
teur radio officials, elected and self 
appointed, who took the time and 
trouble to point out that there was no 
use in complaining about the repeater 
regulations — that nothing could be 
done — that a petition was a waste of 
time - that we should all just depend 
upon the League — I would like you 
to realize that it is indeed possible for 
someone in our country to speak up 
and be heard. It is possible for some- 
one to get action. It may even turn 
out to be possible for rules to get 
changed! 

In this case it was Wayne Green that 
made the outcry — but it could just as 
easily have been any individual con- 
cerned amateur. Space is available in 
73 - and possibly elsewhere for this 
sort of thing. If you speak up 73 will 
back you up. 

IBM TAPES NEEDED 

The tapes for the 73 Magazine 
MTST IBM composer are wearing out 
and we need more. Does any reader 
know where we can get some for a 
reasonable price? Help I 

73 AGENT DOES WELL 

One 73 agent made over S300 at a 
hamfest in commissions — perhaps 
you might look into this? That's not a 
bad pay for a day's work, you know. 
Drop a note to 73 Magazine and send 
some references. 

DAYTON EXPANDS - AT LAST! 

The Hamvention committe has at 
last decided to expand the 
Hamvention to a full two and a half 
days. Thousands of amateurs will 
certainly cheer this decision — as will 
an awful lot of manufacturers. 

Any amateur with more than one 
or two interests in the hobby has had 
a heck of a time getting to the talks of 
importance. With all of the talks 



scheduled in one day, there was 
incredible overlap. DXers missed 
important RTTY meetings - 
delightful SSTV meetings — and so 

forth. With over two full days for 
meetings and talks, these things may 
be able to be spread out a little better. 

The size of the flea market has been 
such that no serious scrounger could 
possibly do it justice in one short day 
— there was just far too much. 

And the manufacturers exhibits 
were so packed with hams that only 
about one in five Hamventioneers 
could break through to ask a question. 
The odds should be a little better next 
year. This will be better for the 
manufacturers too — for they will 
have a chance to talk personally with 
more prospective customers — and 
make more sales — the basic reason 
for the long trip to Dayton. 

The largest hamfest in the country 

can only get larger with this move- 



CASSETTE TAPE CODE COURSE 

73 is offering a cassette tape code 

course that is so simple that the 
average person can learn the code fast 
enough to pass the Novice or Tech 
exam in a few hours. One of the 
beauties of cassette tapes is that you 
can take them with you anywhere — 
at work for lunch break — in the car 
while you are driving - cassette re- 
corders are simple and inexpensive - 
and are useful for dozens of ham 
applications. 

This cassette code course will teach 
the International Morse code at five 
words per minute — all letters, num- 
bers and punctuation. The tape not 
only gives all of these characters, but 

gives them in a very simple order so 
you can start copying code within one 
minute of hearing it. This has got to 
be the easiest way to learn the code 
ever invented. 

The cassette actually has the code 
being sent at about 6 wprn, allowing a 
margin for operator panic when the 
chips are down and the real exam is at 
hand. It makes the 5 wpm code sound 
a whole lot slower — and that is a 
help. 

And wait* 1 1 you get a look at some 
of the stuff you'll be copying on this 
tape — pure Wayne Green, of course. 
You may lose your place the first time 
through when some of the stuff hits 
you. There's no reason why copying 
code shouldn't be fun — right? 

Send now for the 73 Morse Cassette 
Code Course — only $3.95 postpaid 
from 73. 

WAYNE 



73 MAGAZINE 




Dave Ingram K4 TWJ 

Rte. 1 1, Box 499, Eastwood VfL SON 

B/rm/ngham AL 352 10 



SSTV CONTEST ANNOUNCED 

This winter promises high Slow 
Scan activity, and we're kicking it off 
with a Slow Scan Program Contest It 
works like this: Make up your prize 
winning program (6 minutes maxi- 
mum) on a cassette, and send your 
entry to 73 Magazine. They will be 
compiled and reviewed, then forward- 
ed to another "anonymous" judge to 
be reviewed again! Firrai results and 
prize winners will be published. Selec- 
ted frames from winning tapes will 
also find a prominent place in these 
pages. 

All entries will be judged on origi- 
nality, with technical aspects counting 
in the scoring. This contest begins 
now and ends December 31, 1973. Be 
sure to include return postage for 
your tape. 

The purpose of this contest is to get 
more fellows thinking and acting in 
terms of good purposeful programs, 
not just I Ds and CQs. 

Last month I briefly described 
some basic scan conversion techniques 
from the aspect of both solid state 
and dual gun (lithocon) electron 
tubes, I also mentioned Don W9NTP, 
and Art SM0BUO, were developing a 
converter unit that used the 
Thompson TME 1238, a single gun 
storage tube. Since this tube is rather 
unique, [only one electron gun is 
used) I have a brief description this 
month. Figure 1 is a simplified sketch 
of the tube. First the Slow Scan video 
is fed in on Grid 1, and stored on the 
mosaic target. Next, Grid 1 (writing 
grid) is biased to give a constant 
electrong flow. The electrons now 
repelled by the "reading" Grid 5, and 
can be fed to a video amplifier Since 
the reading grid does not affect the 
target (because it doesn't scan it) it is 



SLOW SCAN I 


IDEA INPUT 








umu i 


■ 
■ 

■ 

■ 


SILICON 










MOSAIC 






TARGET 






_ 


t. ■* 








"T> T 


^ j: 


* ■ 

■ 


iMot-ei itrlr? in 
manner 1 




I 




■ 
■ 

■ 
■ 

■ 
■ 






Rudciuil GRID 




GRID 5 

FAST SC AIM 







Fig. 1. Simplified sketch of a single-gun 
storage tube. 



considered a nondestructive readout 
device. In fact, Don turned on his unit 
two weeks after the Dayton 
Demonstration, and his last picture 
was still there! {Of course it wouldn't 
last this long if rt had been constantly 
"read/') 

Our thanks to Dr. Miller for the 
previous info on the Thompson CSF 
tube. I understand Don replaced the 
bad video transistor that caused the 
noisy pictures at Dayton, and now the 
unit is working well. Incidentally Don 
agrees, like many others, digital pro^ 
cessing is probably the better way to 
approach scan conversion from a 
"standstill/' In fact, 3 MOS shift 
registers, driven by red, green, and 
blue Slow Scan information could be 
used to give Slow Scan displayed on a 
color Fast Scan TV in real time, This 
is probably 2 or 3 years away yet. A 
couple of the fellows suggested this 
MOS shift register method over my 
"crt/dichroic mirror" color scheme, 
and I agree this is better. However, for 
the next few years, the tubes and 
dichroic mirrors (advertized in the 
July issue for $4,95 each) should be 
less expensive. 

Here's some more info on the 
weather satellite I mentioned last 
month whose facsimile transmissions 
might be of interest to Slow Scanners. 
At this time the four main satellites of 
interest are ESSA-8 (137.62 MHz), 
NOAA-2 (137.50 MHz), ATS-1 and 
ATS-3 (both on 135.60 MHz). 
ESSA-8 and NOAA^2 are orbital satel- 
lites, with an orbital period of 114 
minutes, inclination of 101 degrees, 
and an altitude of 906 miles. (Orbital 
info is given on W1AW bulletins.) 
ESSA-8 transmits only while the 
spacecraft is in daylight areas, and 
cuts off when it enters a dark area. 
NOAA-2 is said to be transmitting 
continuously. ATS-1 and ATS-3 are 
fixed position (geosynchronous) satel- 
lites. ATS-1 is approximately 4,000 
miles above Venezuela (70 a West/0 " 
latitude). Both of these satellites scan 
(and can be received by) about 1/3 of 
the world. You can get a rough idea of 
this coverage by placing an object 
4,000 scale miles above Venezuela on 
a world globe, for example. Then look 
at the globe from that point, and 
you'll see what the satellite sees. If it's 
"line of sight" (use a piece of string 
from your QTH to satellite) you 
should be able to receive it. ATS-1 
transmits daily at 0130 to 0215 GMT, 
and again at 1400 to 1445 GMT. 
ATS-3 transmits daily at 0730 to 
0815 GMT and again at 2045 to 2130 
GMT. AH of these satellites (except 
NOAA-2) transmit primarily on fac- 
simile using an amplitude modulated 
2400 Hz tone. Maximum amplitude 
(80 to 100%) corresponds to white, 
and minimum amplitude (30 db below 



this) is black. The horizontal line rate 
is 4 per second, (240 lines per minute) 
and a total frame lasts approximately 
208 seconds. NOAA-2 differs only in 
that it has a 48 line per minute rate. 
For satellite copy on a surplus 
deskfax unit, simple video inversion is 
necessary. (Because maximum ampli- 
tude gives the darkest line on current 
sensitive fax paper.) Then we increase 
the drum speed from 180 rpm to 240 
rpm. There are several methods of 
accomplishing this like, for example, 
dividing the 2400 Hz received signal 
by 30 and using this resultant 80 Hz 
to run the motor, thus giving 240 
rpm. Another method of copying pic- 
tures from the satellites is with a 
converter (for obtaining proper hori- 
zontal and vertical timing, a video 
demod/amplifier, and "front end" 

limiter) feeding a 'scope or Slow Scan 
monitor. A camera is then used to 
photograph the screen (three minute 
picture. . .strictly Sloooow Scan!}, 
thus reproducing the picture. Special 
thanks go to Bob WA7MOV, for his 



QTH 




ANGLE OF ELEVATtOM 

- -^ SATELLITE 



LOBE MILEAGE SCALE 



Fig. 2. Setup for measuring satellite 
antenna positioning. 

help in compiling much of the above 
info. I've also received word from R. 
L. Drake's Service Manager, Their 2 
meter gear should receive okay on 136 
MHz, although they have not tried it. 
Possibly the 2 meter rig's crystal 
oscillator coil may need slight retun- 
ing. (Why shouldn't it work. Many put 
crystals in 2 meter rigs to pick up 
Police calls on 150 to 160 MHz.) Mr. 
Frost of R, L. Drake says crystals are 
$7.50 each for the TR-22 and are not 
returnable. Also the TR-22 bandwidth 
is 20 kHz. ,. fine for satellite copy. 
Say — how about a Bearcat "scanner" 
set up to copy all the satellites. 

Barry VK5BS, recently vacationed 
in the Fiji Islands, carrying quite a bit 
of SSTV info in hopes of getting some 
of their hams on slow scan. (Two 
packs of info I sent him arrived just a 
couple of days before his departure!) 
Hopefully, we will soon know the 
status of SSTV in Fiji. 

And finally, the Independent Side- 
band boys are gathering on Tuesday 
nights between 14.230 and .240 kHz 
for I SB SSTV operations. If you Ye 
interested, here is the place to be to 
get in on the action. 

, . .K4TWJ 



OCTOBER 1973 





■ --'-»£$&ixsnmM!i!*i «.. i. . -. 



magazine's 

a single frame of your RULES: 

^tlflplc (IT yCfl /? flfl m ^ minute maximum time length 

longer enough — you 've 
got more talent than 



that 



nows your 



chance to prove it? 




First Prize 



ROBOT Model 61 

Fast Scan Viewfinder 
Other prizes to be announced. 



Subject matter is limited only to 
your imagination — anything goes. 

Label cassette with your return 
address and include sufficient re- 
turn postage. All programs will be 
returned. 

Decisions of the judges will be 
final. 

Contest starts now — entries must 
be mailed before December 31, 
1973. 

Use only enough time to effec- 
tively bring across your idea. An 
idea that is best expressed in 2 
minutes will turn into a horrifying 
bore if interspersed with 4 minutes 
of filler. 

Don't repeat frames except for a 
purpose — the closed-circuit quality 
of tape makes repeating 
unnecessary. 

Please do not send a script or 
explanation of your program. Since 
Slow Scan is a visual media, every- 
thing you want included in your 
program should be on your tape. 

Send your entry to: Slow Scan 
Contest, 7 3 Magazine, 
Peterborough, NH 03458. 



73 MAGAZINE 




Gus Brown) ng W4BPD 
Drawer "DX" 
Cordova, SC 29039 

SOME QSL INFO: 

A26AC via 4S7YL 

AP2MR via Callbook address 

C29ED via VK3TL 

CT2AZ via W0 JHY 

EL7D via DK3IA 

EL0 Q via LA9GG 

EL0S via YU3RCZ 

ET3USD via WA4HVQ 

F0ALN via K4II 

FBflZB via F8US 

GC5AGA via K4II 

HB0AVB via DK3ST 

HW3UIT via F9QE 

JW4EJ via SM5BCS 

JW7FD via U\3UC 

JX6VO via LA IRQ 

JX9TM via LA9TM 

SVPWY via WApVPX 

M1C/D via I4FTU 

TJ1BG via K4WQS 

TY7ABM via DL7JJK 
WI9ANG via WA9DZL 
WF20C via W2HAQ 

WS4SKY via WA3NAN 
3D2JA via W2QVC 

5Z4KL via GM3VLB 

7W3ITU via 7X-buro " 

9X5MV via DJ2AZ 

If you want to see more DX QSL info 
each month let me know because I can 
give you a lot more than the above. 
WTW VERIFICATION POINT: 
I wish to announce that we have a FB 
DX Club that has volunteered to act as 
our WTW {and 73-73-73. too) verifi- 
cation point for all of W/Kl, W/K2, 
W/K3 land. More or less centrally 
located too; 

The Thomas A, Edison Amateur Radio 
Assn. 

c/o WB2FVO Club QSL Manager 
William W, Inkrote, Jr. 
52 Elliot Place 
Edison, N J. 08817 - US.A. 
Be sure to send them all your cards to 
be checked. Send along the $ 1.00 to 
help the expenses for your certificate, 
and also send along enough extra for 
the class of postage to return your 
cards to you. They will give you very 
fast service I am sure - I will mail you 
the certificate that you qualify for 
when they notify me that your cards 
have been checked and that you have 
qualified O.K. 

We still need more verification 
checkpoints, how about your club ? 

I am at last getting things fixed up 
here and will be seeing all of you on 
or near 14220 sometime between 
about 2200 to 2400z. 73 till next 
month - de, -^U4- B P D 




RATARAMA 

The Mount Airy VHF Radio Club, 
Inc., presents the annual Pack Rat 
Hamarama, Sunday October 7, 1973, 
at the Warwick Fire Co,, Jamison, Pa. 
The Warwick Fire Co., is located on 
Rt. 263 North of Philadelphia. 
Activities include a giant flea market, 
auction, and an amateur TV demon- 
stration. Festivities begin at 10 AM. 
Food concession on premises. Regis- 
tration is $1.00, flea market tables or 
tailgate safes, $2.00. Talk in on 
146.52 and 52.525. For furthern in- 
formation contact: Dave Zimmerman 
W3ZD, 520 Centennial Rd., War- 
minster PA 18974. 

MIDWEST CONVENTION 

The ARRL Mid-West Convention is 
being sponsored by the Lincoln Ama* 
teur Radio Club this year. It will be 
held on October 6 and 7 f 1973, at the 
Villager Motel and Convention Center 
in Lincoln, Nebraska. It promises to 
be one of the largest in the Mid-West, 
drawing on radio amateurs in a four 
state area and more. For information 
contact: G3UGH/W0. c/o Lincoln 
Amateur Radio Club, Inc., P. O. Box 
5006, Lincoln, Nebraska, 68505, 

MID-SOUTH HAMFEST 

The Mid-South ARA is holding its 
1973 Hamfest on October 6 and 7, at 
the State Technical Institute in 
Memphis TN. There will be a MARS 
meeting, FM Symposiums and other 
activities. Contact: Harry Simpson 
W4SCF, c/o Mid-South ARA, 1830 
Macaulay Ave., Memphis TN 38127. 

CHAUTAUQUA AUQTION 

The Chautauqua County NY FM 
Association's third annual auction will 
be held October 13, 1973, at Shore 
Acres Boat Yard, Bemus Point NY. 
For further information write to 
Robert Greenwald WB2YQO, Rte. 2, 
Box 76, Jamestown NY 
14701. 

OCTOBER REPEAT 

A special meeting of the Illinois 
Repeater Council will be held on 
Saturday, October 20, at Southern 
Illinois University- Hosted by 
WR9ABU, all Illinois and adjacent 
repeater representatives are cordially 
invited. Contact; Kontact Kim King, 
Sec. IRC, 1618 Linden, Des Plains IL 
60018,312-824-8419 



TAMPA BAY 

Seven Tampa Bay Area clubs have 
joined forces to present, perhaps, the 
largest ham gathering in the State of 
Florida. Over $2500 worth of prizes 
will be awarded by drawings. First 
prize will be a complete Galaxy 500 
station. Registration is S2. It will be 
held on October 6 and 7, 1973, at the 
Electrical Building, Florida State Fair- 
ground on N. Boulevard, 2 blocks 
north of Kennedy Boulevard, begin- 
ning at 8 AM local time, inquiries may 
be sent to Mr. George Dixon 
WA4VQT, 12915 Veronica Ave., 
Tampa FL 33612, In addition, we an? 
providing an information station on 
the air Monday, Wednesday and Fri- 
day, 7 - 7;30 PM EST and Sunday, 
10 - 10:30 AM on 7280 kHz. 

ADRIAN HAMFEST 

The Adrian Amateur Radio Club 
Inc, of Adrian Michigan, presents their 
fall Hamfest, Sunday October 14, 
1973, from 8 AM to 3 PM, at the 
Lenawee County Fairgrounds on Dean 
St Talk in on 1812 kHz - 3935 kHz 
- 52.525 MHz - 146,46 MHz - 
146,52 MHz - and 146.94 MHz. 

All buyers, sellers and visitors are 
welcome. Plenty of refreshments and 
prizes. Cost $1.00 in Advance, $1.50 
at the gate. Tables $1.50 per half 
table. For information on tickets or 
tables write to the Adrian Amateur 
Radio Club, P. 0. Box 26, Adrian Ml 
49221. 

FAR-OUTing 

The Foundation For Amteur Radio 
will hold its annual Hamfest at the 
Gaithersburg Fairgrounds, Gaithers- 
burg MD, on Sunday October 21, 
1073. Featured is a large flea market, 
food service, exhibits, ladies events, 
supervised children's program and 
many prizes. Main events are all in- 
doors. Picnic grounds and free parking 
available. Will be held rain or shine. 
Participation fee $1.50, sales space 
$5/00, Talk-in service provided. Near- 
by motel rooms available. For info 
write or call Bill Miller K4MM f 10919 
Woodfair Rd., Fairfax Station VA 
22039. 703-893-2450. 

TERRY SWAP 

The Terry County Amateur Radio 
Club's 19th Annual Brownfield Free 
Swapfest will be held on October 14, 
1973 in the National Guard Armory, 
Brownfield, Texas. Doors open at 
6:30 AM and Swapfest activities last 
until 3:00 PM. No registration or 
admission fees! Door prizes. Largest 
Amateur Radio flea market in Texas! 
AH exhibitors, amateure, CBers and 
families welcome. Free parking and 
trailer camping in Coleman Park a& 
jacent to the Armory, 



OCTOBER 1973 





f REPEATER UPDATE 



LISTENING 

§4 76 88 73 70 64 82 












AL 


WR4ACK 


Oritur 


145.40-14700 


At 


WR4ACB 


B'tmiafum 


14fi.tG-14-G.76 

14B.13-I4fi.7fi 


CA 


WR&ACB 


Li Hibra Hit 


146.11H46.70 


CA 


WR6ABX 


Wttodlmd 


146.37-146.97 


CT 


WR1ABA 


Sftniburv 


146.2214612 


CT 


WR1ABC 


Tflfiififton 


223 06224.66 


FL 


WR4ACV 


fioci ftllon 


146.22-145 82 


IA 


WRIABS 


Ofrtflport 


1462214682 


IL 


WR9A9X 


Rock Iriind 


146.34- 146.94 


III 


WH9A8P 


ImJunipolis 


14C.1 6-146.76 


III 


WR9A9W 


KobofflG 


146JM46.91 


KS 


WfllABO 


PrTBbwrf 


145.13 146.73 


KV 


WH4ACQ 


Asttlifid 


146.34 146.94 


MA 


WRIAiO 


Worcerttf 


146JM46.97 


MA 


wniAtv 


Witthtrn 


140.04 146,54 


MA 


WHlAlK 


F onfall ra 


146.31 -146.91 


MD 


WR3ABQ 


Hirmiitf PL 443.55-4W.95 


MO 


WRiABC 


Bonn* Ttm 


146 29 146 96 


NY 


WR2ABF 


Rochrttti 


146,19146.79 


OH 


WRQASA 


ML Vprnon 


146 T9 146.79 


OH 


WH6A9C 


Draltnd 


146,16-146.76 


OH 


WRIABF 


Dayton 


146 34 146.94 


OH 


WHBABG 


Springfield 


146.13-146,73 


OH 


WH5ABH 


Hudson 


14611446,61 


OH 


WRtABJ 


Mmrcomentown 


146 16-14676 


OH 


WRBABO 


Chtlltcacht 


146,261 45.85 


OH 


WRHA&P 


Cincinun 


146_2S 145.86 


OH 


nnflnoR 


Diitwtff 


T46.37-146J7 


OR 


WR7ABJ 


Wettport 


146.1B-145.7fi 


PA 


WR3ABF 


Valley f Offf 


Plinned 


PA 


WH3ABG 


V*II«Y Foifi 


Planned 


PA 


WR3ABH 


ViMty FofOf 


222,34223,94 


PA 


WR3AB! 


ViHty Forgt 


14634 146,94 


TX 


WRSABM 


Brownftild 


146.2 2- 146. 82 


VA 


WR4ACW 


Richmond 


146.29146,88 


Wl 


WR9ABV 


tikt Ginavi 


146J7146,97 


Wl 


WR9ABS 


Mifwoukee 


146.25-1 46.85 




CONTESTS ~z 




3ET 



Tom DiBiase WB8KZD 
708 6th Avenue 
Steubenvttie OH 43952 



Oct. 6-7 
Oct. 6-8 
Oct. 13-14 



CONTESTS 

Sept 29-Oct. 1 Delta QSO Party 

New Mexico QSO Party 

California QSO Party 

RSGB 21/28 MHz 

Telephony Contest 

Oct. 20-21 RSGB 7 MHz CW Contest 

Oct. 20-22 North Carolina QSO Party 

Nov, 2-5 CHC/FHC/HTH 

QSO Party 

RSGB 7 MHz 

Phone Contest 

QRPPCWQSO Party 



Nov. 34 



Nov. 5-1 1 



Month 
New Mexico QSO Party 

From 220 GMT October 6 to 0100 
GMT October 7; 0200 GMT to 0600 
GMT and 1800 GMT to 2200 GMT 
October 7, 1973, Frequencies are 65 
kHz up from the bottom of each CW 
band, phone near the edge between 



General and Advanced frequencies, 
Novice near the middle of each Novice 
band. Only NM stations call CQ 
Contest near these frequencies, 
Exchange QSO number, RS/T and 
QTH (county for NM, state, province 
or country for others)* Stations may 
be contacted only once on each band, 
and again if he changes counties. 
Intrastate NM contacts are valid. 
Score 1 point per QSO. NM multiplier 
is total states, provinces, countries and 
NM counties, Non-NM use total NM 
counties for multiplier. Appropriate 
awards. Full log data, including 
exchanges, should be sent to Bill 
Wageman, K5MAT, 35 San Juan, Los 
Alamos NM 87544 by November 1, 
1973. 

California QSO Party 

From 1800 GMT October 6 to 
0600 GMT October 7, and 1500 GMT 
October 7 to 0300 GMT Octber 8. 
Same station may be worked once per 
band/mode. Exchange QSO number, 
RS/T and QTH (county for California, 
ARRL section or DX country for 
others), California stations work 
anyone. Non-California work 
California only. Score 1 point per 
QSO. Multiply total QSO points by 
total California counties worked or 
total ARRL sections (including 
California) and DX countries worked. 
Frequencies are 3560, 7060, 14060, 
21060, 28060, 3880, 3980, 7280, 
14280, 21280, 21380, 28580, 3725, 
7125, 21125, 28125. Appropriate 
awards. Logs must show date, time, 
band, mode, exchanges sent and 
received. Logs can't be returned. Be 
sure your call is on each page. A 
summary sheet is required showing 
counties, ARRL sections and DX 
countries worked, breakdown of 
QSOs per band and scoring. Include 
your name, call and address in large 
block letters. Mail logs before 
November 7, 1973, to John Minke, 
W6KYA, 6230 Rio Bonito Drive, 
Carmichael, California 95608. Include 
a large SAS for results. Comments are 
encouraged and appreciated. 

North Carolina QSO Party 

From 1800 GMT October 20 to 
0600 GMT October 21 and from 1300 
GMT October 21 to 0200 GMT 
October 22, 1973. Each station may 
be worked once per band/mode and 
again if operated portable or mobile, 
and with each county change. 
Exchange QSO NR, RS/T and QTH 
(county for NC; state, province or 
country for others. NC score 2 points 
for out of state QSOs, 1 point for 
QSOs with other NC stations, 
multiply total points by number of 
states and provinces worked. Out of 
staters score 2 points per QSO and 
multiply total by number of NC 



counties. Frequencies are 3575, 7090, 
14070, 21090, 28090, 3710, 7110, 
21110, 28110, 3810/3900, 7290, 
14290, 21310, 28510 (all are 
plus/minus 10 kHz). While on 3575 
try not to QRM the Carolina's traffic 
net which meets at 2300 GMT and 
0200 GMT near that frequency. The 
entire 6 and 2 meter bands can be 
used, and repeater QSOs count. 
Appropriate awards. Mail logs before 
November 25, 1973 to Charlie Wells, 
K4SK1, Rte 8, Box 414, Greenville 
NC 27834. 

By the shadow on the wall I see 
that it's time to wrap up another 
column. Until next time, "CQ 
Contest, CO Contest, CQ Contest/' 

Tom WB8KZD 



NEW 




PRODUCTS 



SBE Scanvision 




The W2NSD/1 Scanvision package being 
tested with special zoom lens. 

SBE has come up with a beautiful 
slow scan system — complete with a 
built in cassette tape recorder. This 
system makes it duck soup to put 
together your own tape 
programs, . .and let's face it, this is the 
way slow scan has gone. 

With tape reproduction of a slow 
scan usually identical with "live" 
camera work, it is only logical that 
most ops have opted for using tape. It 
doesn't take long sitting still for eight 
seconds in front of the camera — and 
then jumping up to refocus (which 
isn't all that fast a process unless you 
have a fast scan monitor too) on a 
menu board for giving your name, 
location, signal report, and perhaps a 
QSL — before you are thinking 
seriously in terms of tape* 
Unfortunately, many of the cheaper 
recorders are not adequate for the job 



8 



73 MAGAZINE 



REPEATER OWNERS 



Don't Take Chances. SENTRY offers custom made crystals made exactly 
to your specifications. When it comes to crystals for your repeater, BUY THE 
BEST -SENTRY. 



.'.■.'.'.Vi'.'lViViVrVA 



, Vfc"| , B"-l , B a | , -"| , -"l - ' ■ ' ' ' ■ 



.-.-.'.■ ■■l'd' 






y< 



■ ;■ :>:£*# 



REPEATER USERS 



If you want reliable access to the repeaters in your area, you want and 
need SENTRY CRYSTALS. SENTRY CRYSTALS are custom made for your 
rig. We don't stock a large quantity of crystals for a certain frequency and 
hope you can tweak them to frequency in your rig. We do offer FAST service 
on crystals made especially for you and your rig. If you want reliable, 
on-frequency operation, INSIST ON SENTRY. 




SENTRY MANUFACTURING COMPANY 

Crystal Park, Chickasha, Oklahoma 73018 

PHONE: (405) 224-6780 

TWX -9 10-830-6425 



OCTOBER 1973 




mm 



and there are little squiggles which 
result from not too steady tape drive 
mechanism. 

Once you are set up with a good 
recorder you can start putting 
together short tape programs — a view 
of your shack — picture of you — 
your wife - with titles. You can tape 
the OTH and CQ calls. You can work 
up a short program showing some of 
your other interests than amateur 
radio — which is r.ot only interesting 
to viewers, but affords plenty to talk 
about if you match an interest with 
someone else. 

You can put together a program of 
your QSLs for each country worked, 
unless you are one of the real slow 
scan DXers with 73 countries worked, 
in which case it would take about ten 
minutes at one card per frame, to 
show the bunch. Even so, that might 
be a little better than some of the 
dumb cartoons that are being 
shown- 

The SBE Scanvision camera has one 
very handy feature — an automatic 
contrast control. The less controls you 
have to diddle with the better. There 
•S a manual over-ride for knob 
twisters. 

After using the Scanvision for 
several weeks, there are several things 
that stand out — the ease of hooking 
it up for use — the beautifully sharp 
picture — the convenience of the built 
in tape deck — and {most of all) the 
fun of actually seeing the fellow you 
are working. 

The Scanvision manufacturer also 
makes commercial broadcast 
television cameras and this is obvious 
when you open the camera and take a 
look at the construction 
techniques. . .beautiful! This shows up 
in the picture too — just take a look at 
a grey scale on this monitor and see 
how much more you get than you 
might expect. 

Linear Systems is to be 
congratulated for making this superb 
slow scan unit available — slow scan 
will, it seems certain now, be one of 
the big growth aspects of amateur 
radio during the next few years. Once 
you see it in action you are hooked. 



TONE PADS 

Interface Technology has 
introduced a Touch -Tone generator 
designed to aid repeater and auto- 
patch users. The unit generates the 12 
standard frequency pairs used for 
Touch-Tone dialing by the telephone 
companies. It is designed so that the 
output can be used in several ways. 
For one, a speaker included in the kit 
can be mounted internally and the 
unit simply held up to the micro- 
phone. The speaker can also be 
mounted in a small, remote case (not 






supplied) and connected by a cable to 
the generator. This allows the user to 
position the generator on a table or 
desk while the speaker is held up to 
the microphone, A third approach is 
to wire the unit directly into the 
microphone circuit, eliminating the 
need for the speaker altogether. 

There are no switches or controls 
on the unit other than the key pad, so 
no current is drawn from the standard 
9-volt transistor battery until the 
operator touches a key to generate a 
tone. This feature insures long battery 
life and simplicity of use. The unit is 
lightweight and packaged in an attrac- 
tive black molded plastic case, For 
more information contact: Interface 
Technology, Inc., 10500 Kahlmeyer 
Dr., St. Louis, Missouri, 63f32. 
314-426-6880 

SBE SCANNERS 




Linear Systems has announced the 
introduction of a complete line of 
scanners which cover frequencies from 
30-470 MHz. The entire line, known 
as the Sentinel Series, consists of six 
separate models. 

The Sentinel includes 8 channels 
for scanning, lock-out switches, man- 
ual or automatic scan operation and 
AC/DC capability. An important fea- 
ture of the Sentinels is the priority 
channel which assures the reception of 
the most important channel. All come 
equipped with cord/plu sets for either 
12V dc or 115V ac operation* Also 
included is a screw-in telescoping an- 



tenna for VHF and where applicable a 
separate VHF plug -in antenna. The 
receivers have excellent sensitivity of 
.3jj V with selectivity rateo at -6db @ 9 
kHz, Audio output is 4 watts and the 
receivers are designed to operate over 
the temperature range of -20 'C to 
+50 'C, The specific model numbers 
and frequency ranges are Sentinel I 
high-low VHF, Sentinel M high band 
VHF, Sentinel 111 low band VHF, 
Sentinel V UHF r Sentinel VI UHF 
high band, and Sentinel VII marine 
VHF. 

For further information contact: 
David K> Bradley, Vice President, Mar- 
keting, Linear Systems, inc., 220 Air- 
port Boulevard, Watsonville CA. Tele- 
phone; 408 722-4 177. 




ooxTEsrr 




Jane 

OCEANS' DE 




Jane Rice WA60ZS, captured the 
heart of our contest judge this month 
with her homebrew silkscreened 
entry. Win a one year subscription to 
73! Send your QSL to: QSL Contest, 
73 Magazine, Peterborough NH 
03458. 



CANADIAN GOVT. 
SUPPORTS REPEATER 
GROUPWITH GRANT 

$6,772 AWARDED 



State-of-the-art thinking on the part 
of Canada's Department of National 
Health and Welfare has prompted a 
$6,772 grant to a repeater group in 
Courtenay, B.C. Realizing the impor- 
tance of VHF repeaters in providing 
emergency communications during 
times of disaster, the grant was endor- 
sed whole-heartedly by civil defense 
authorities*. The planned repeater will 
provide communications within a 150 
mile radius. 

Meanwhile, back at the FCC. . . 



10 



73 MAGAZINE 



♦:♦:♦:♦:♦:♦:#:♦:♦:♦:♦:♦:♦ 



Caveat Emptor? 



♦:♦:♦:♦:♦:♦:♦:♦:♦:•:♦:♦:♦. 



Price — $2 per 25 words for non-commerciaJ 
ads; $10 per 25 words for business ventures No 
display ads or agency discount. Include your 
check with order. 

Deadline for ads is the 1st of the month two 
months prior to publication. For example. 
January 1st is the deadline for the March issue 
which will'be mailed on the 10th of February, 

Type copy. Phrase and punctuate exactly as 
you wish it to appear. No all-capital ads. 

We will be the judge of suitability of ads. Our 
responsibility for errors extends only to print- 
ing a correct ad in a later issue. 

For $1 extra we can maintain a reply box for 
you. 

We cannot check into each advert iser, so Caveat 
Emptor . . . 



WESTERN UNION DESK FAX trans 
ceiver manual: Complete theory of 
operation, adjustment, lubrication, 
preventive maintenance, troubleshoot- 
ing, parts list. Includes all schematics 
and mechanical parts drawings. $3.80 
postpaid. Bill Johnston, 1808 Pomona 
Drive, Las Cruces, New Mexico 
88001. 

"WANT VIBKOPLEX carrying case. 
Advise condition, age and price. P. O. 
Box 191 r Rye Beach NH 03871." 

2 METER FM Brand new HR-2A 
94/94, 22/82, Hustler 5/8 trunk lip r 
warranty, perfect. WA6LZH, 4130 
Carson, Oakland CA 94619, 
415-530-7187, 

COLLINS MP-I Power Supply, new 
never used, trade for 516F2, PM-2, 
312B4, HT220, or ST-6. Want to buy 
32S1. Fred Slaughter, WB8IJX, 3636 
Douglas, Toledo, Ohio, 43613. 

"DIGITAL MULTIMETER - 3 % 

digit franklin model 500, - $60. 
Chart recorder, - $20. 6' x 19" rack 
cabinet - fully enclosed, - $40. EMC 
5 MHz Oscilloscope, - $90. Sell or 
swap. Jim Einolf, 1218 W. Ionia, 
Lansing Ml 48915/ 



Tf 



FOR SALE: GE Porta-Mobile 2m, 10 
watt portable with nicad, 94/94, 
22/82, $300. HT-22Q, two watt, two 
channel with charger, $275, MQTRAC 
"A" model transmitter and power 
supply, $35. MOTOROLA pocket- 
receiver with nicad, $45. MIDLAND 
CB? - $25. Gary Eberle, WA6CW, 
1655 Via Escondido, San Lorenzo, 
CA 94580. 

WANTED: Facsimile equipment, 
weather satellite equipment and/or 
information, RTTY machines 100 
wpm. Ken DeBrecht, WB6NOV, P. O. 
Box 1086, Novato CA 94947. 



EQUIPMENT FROM 73 

The following list of gear, unless 
otherwise noted, consists of brand 
new equipment purchased for testing 
purposes only. 

Cap-Corn 40m solid state 

SSBxcvr $150 
Heath IB-101 counter with 

Vanguard Scaler $250 

Clegg 27B 2m xcvr S380 

IC-22 2m FMxcvr * $246 

Midland 1 3500 2m xcvr $200 

Midland 1 3509 220 xcvr $200 

Tempo CL-220 220 xcvr $200 

Clegg FM-21 220 xcvr $255 

Regency H R-6 6m xcvr $1 90 
HR2MS 8 channel 

scanning 2m xcvr $255 

TME-H-LMU 16 channel rcvr $255 

Digital Logiclocks $ 80 

Dycom 2m repeater $425 
Wilson 7 element 10 & 15m 

beam (pick-up only) $250 

Waller 60A power supply $105 
Standard sr-c 120/5 power sup. $ 44 

Gladding 1 2V power supply $ 60 

SBE Scannavision $650 

Robot Monitor $265 

Robot Camera $265 

AX 1 90 amateu r rcvr $200 

SX 190 SWL rcvr $200 

Pickering KB-1 keyboard $200 

TPL 502-B 2m Amp 1 w/40w $1 10 

TPL 502 2m Amp 10w/45w $ 90 

Kenwood TS-51 1 S SSB xcvr $350 

Heath HW-202 w/encoder $1 80 

Heath HWA-202-1 $ 30 

Heath HA-2022 amplifier $ 70 

FACSIMILE PAPER for Desk Fax 
units: $1.95 per box, 6 boxes for 
$10.50; for weathermap recorders; 
$4.25 per box, 4 boxes for $16. Jim 
Cooper, P, 0. Box 73, Paramus IMJ 
07652. 

tOR SALE: Gonset III 6 meters 
"MINT 1 , - $100.00. Gonset III 2 
meters AM and FM, excellent, - 
$145.00. WANT: Hallicrafters HA-2. 
Jim W1VYB, 53 Loth rap St, Beverly 
MA 01915, 617-922-3850, 

OPAQUE/TRANSPARENT PC/IC 
TAPES. SPECIFY 1X, 2X, 4X. TWO 
8 x 10 Assortment sheets plus art 
worksheet - $3.50. Eugene Wiener, 
523 Morgan No. r Minneapolis, Minn 
55404. 

HOOSIER ELECRONICS - Your 
ham headquarters in the heart of the 
Midwest where only the finest ama- 
teur equipment is sold. Individual, 
personal service by experienced and 
active hams. Factory-authorized deal- 
ers for Clegg, Drake, Genave, Re- 
gency, Standard, Hallicrafters, Ten- 
Tec, Kenwood, Tempo, Midland, 
Galaxy, Hy-Gain, CushCraft, Mosley, 
Hustler, Ham-M, Sony, plus many 
more. Orders for in-stock merchandise 
shipped the same day. Write or call 
today for our quote and try our 
personal, friendly Hoosier service, 
Hoosier Electronics, R. R. 25, Box 
403, Terre Haute, Indiana 47862. 
812-894-1297. 



"Don and Bob" new guaranteed buys. 
Discount prices, full warranty. Write 
for low prices on following; HYGAIN 
TH6DXX, TH3MK3, 204BA, 
DB1015A, 402 BA; Mosley CL33, 
CL36, S402; Triex MW50, MW65, 
W51 (FOB, Cal); Clegg FM27B; Mid- 
land 13500, 13509-W-T; Regency 
HR2B r HR212; SBE 144 $199,95; 
SBE 450 TRC converts 2mFM to 
3/4m ($179,95 list) $149,00; Stan- 
dard 826MA, 146A; Ham-M $99.00; 
TR44 $59.95; AR22R $31.95; Belden 
8448 rotor cable lOrf/ft; 8214 RG 8 
FOAM 17tfft; 8237 RG 8 1 5d/ft; 
Amphenol PL259 49c?; Hallicrafters 
FPM300 DEMOS, NEED FACTORY 
WARRANTY REPAIR $460.00 ea; 
Used guaranteed; Collins 75A4 
$345.00; Kenwood R599 $300.00; 
T599 $350.00; Hammarlund HQ180 
$250.00; Heath SB300 $250.00; Write 
Quote Swan, Eimac, Rohn tower; 
3/16" cable clamps 18d; Motorola 
HEP 170 epoxy diode 2.5A/1000 PI V 
29d, $25/100 LOT; Motorola Semi- 
conductor Data Series $7,50; Calrad 
KW dualmeter SWR-relative power 
meter, to 150 MHz $15.95; MOT MC 
1709CG OP AMP (709) TO 5 39 tf; 
Write items not listed. Shipping col- 
lect. Madison Electronics, 1508 
Mc Kinney, Houston, Texas 77002. 
713-224-2668 Ni te/ weekend 
713-497-5683 

OLD (ANTIQUE) Radio Buffs, Re- 
pairers for sale, in working order. 
Complete (16 Vol.) repair manuals — 
thousands of service data, schematics, 
etc., almost ail makes from the 
Twenties to the Forties — Gernsback 
Official Man. Volumes 1 to 7 (1937) 
plus Riders Volumes 8 thru 14 
(1944), plus Volume 5 (1934) and 16 
(1945-1946). Atwater Kent Model 35 
battery radio (1924). Majestic "B" 
battery eliminator (1928). Standard 
Metal Co. 19" upright horn loud 
speaker (1925). 16" cone Western 
Electric Model 540AW magnetic 
speaker (1928). Cathedral type 
Crosley table model radio (1932). Old 
books; old tubes; telegrapher's sound- 
er, key; etc. W. C. Motz, 219 Elm St., 
Pittsburgh PA 15218, 412-371-1580, 

MEMPHIS AREA HAMFEST, 
Sunday, October 7, at State Technical 
Institute, conveniently located on 
Interstate 40 at Exit 11. Tennessee 
Section ARRL Convention in 
conjunction. ARRL Forum, MARS 
meetings, prizes, Flea Market, XYL 
entertainment. Informal group dinners 
Saturday night. Talk in on 34-94 and 
3980. All your friends will be there! 

COMPLETE 36 page QSL catalog, 3rd 
edition. New "SPARKLING" QSLs. 
Hundreds of cuts, ten report forms, 
thriteen colored stocks, 25tf. Ten 
sample QSL cards. Cornell son's 
Quality QSLs, 321 Warren St., N. 
Babylon, N, Y. 11704. 

CANADIANS - FREE 120 page elec- 
tronics catalog ETCO-B, 464 McGill, 
Montreal, 



OCTOBER 1973 



11 



*v 



H 




" . * . a mu.it for Jnv f>n»* 
using an inexpensive 
receiver or a sideband 
transceiver on our 

cto h d ed C ^ ban ci -." 



(73 Magazine test report} 



Our a-BOK audio fillet f«tur«; B.ndwltfth CONTINUOUSLY VARIABLE from 

30 Hi (fllmoit 100* sharper thnn moil Ketfrtl) to 2kHa. Aetr*<r film (noaoil»|. No 
Imurtlon Ion. Not a breadboard, Rajidy to plug into ANY rcvr/ncvr. Onvet phon« 
or «xt, ipkr, omp. Full intfruttiorti. In uit worldwide. Plug one Into your ncaluar 
todiyl . , . Only Si 7.85 + S) tapping in U.S. JAdd SaJei Tax in Ctl.l tQ day 
morwvbiick guafsnlia. SEND FOR FREE LITERATURE AMD TEST REPORTS. 

I A1ITER 

^llV ■ ■ ■■ Box 1494L, Canoga Perk, California 




I - i i 



Shipments against our orders placed 
months ago are arriving daily. No long 
wait for the world's most popular ham 
gear. 

SER VING HAMS for 35 YEA RS 

ELECTRONIC DISTRIBUTORS, INC 

I960 Peck Muskegon, Ml 49441 

Tel.(616)-726-3196 
HRS. 8:30 -5:30 SAT. 9 -4 



KITS 



Ci Sub-Audible tone 
Decoder S9.95 




i\m 



Encoder $8.95 



Compatible with all sub-audible tone systems such as 
Private Line, Channel Guard, Quiet Channel, etc, 

G*ass epoxv PCB's & silicon xstrs throughout, 

Any r&eds except special dual coil types may be used. 
Motorola, G.E.. RCA, SDL., Bramco, etc. 

All are powered by 1 2 vci 

Use on any tone frequency 67 Hz to 250 Hz 

Small size 1.5 k 4 x ,75" 

All pans included except reed ;nd reed socket 

Postpaid - Calif, residents add 5% sates tax 

COMMUNICATIONS SPECIALISTS 

P.O. Box 153 BreaCA 92621 



& 



(lhl»"MNI) 



EXCLUSIVE 66 FOOT "*" — "^ 75 THRU 10 METER DIPOLE 

NO TRAPS - NO COILS - NO STUBS - NO CAPACITORS 

futty Air Tested — T h ousand* Already in Use 



E 










#16 40% Copper Weld wire annealed so it handles like soft Copper wire—Rated for better than full legal power AM/CW 
*r SSB Gonial or Balanced 50 to 75 ohm feed line — VSWR under 1 ,5 to 1 at most heights— Stainless Steel hardware— 
Drop Proof Insulators— Tern fie Performance — No coils or traps to break down or change under weather conditions— Comp- 
letely Assembled ready to put up— Guaranteed I year— ONE DESIGN DOES IT ALL; 75 1 OH D— ONLY $12.00 A PAND» 



Model 75 I0HD $60. 00 
Model 7520HO $50.00 



$6 Ft 75 Thru 10 Meters 

66 Ft 75 Thru 20 Meters 

Model 80 40HD $42.00 



ORDER DIRECT OR WRITE FOR 
FULL INFORMATION 



(IMP"fliND 



Model 75-40HD $40.00 

Model 40 20HD $33.00 

69 Ft 80-40-15 Meter (CW) 

300 S. Shawnee 
Leavenworth, Kansas 66048 



66 Ft 75 Thru 40 Meiers 
35 Ft 40 Thru 20 Meters 



OR THRU YOUR FAVORITE 
DISTRIBUTOR 



More CAVEAT EMPTOR 

WANTED: ARC-5/VHF components. 
Mounting Backs MT-65 and MT-71. 
Control Unit C-42, Junction Box J-28. 
Also need connectors. WB8NLM, 146 
Schonhardt St., Tiffin OH 44883. 

DESK FAX TRANSCEfVERS as re- 
moved from commercial service 
(working). $14,95 each, or S25 pair. 
Jim Cooper, P. O. Box 73, Paramus 
NJ 07652. 

MOBILE IGNITION SHIELD gives 
more range, no noise. Everything from 
economical suppression kits to custom 
shielding. Literature, Estes Engineer- 
ing, 543 S West 184th Street, Gar- 
dens, Calif., 90248 



ROCK CRUSHER - Hallicrafters HT 
33A Linear $200, - HT37 $150, - 
SX 101A $T50, - NCX3 TR^Band 
$150, - NCXD $50, - HT40 $35, - 
WA8IYL, 419-492-2317. 

FOUNDATION for AMATEUR 
RADIO annual Hamfest Sunday 21 
October 1973 at Gaithersburg Mary- 
land Fairgrounds. 



COLLINS FOR SALE: Individual 
prices are indicated. For package deals 
please write. 32S3 SN 12091 $650, 
75S3 SN 14276 $600, KWM 2 A SN 
1 1535 $750, 516F2 P. & $75, 312B4 
station control $125, 30L1 linear amp 
$350. Jack Aviv, WA2KNC, 106 
Glenn Avenue, Lakewood NJ 08701. 



WANTED: RD 92/UX fax recorder. 
Need several mechanical drum sub- 
assemblies. Don W1GBO, Box 803, 
North Falmouth MA 02556. 

"BRAND NEW: Clegg 66er in origi- 
nal factory carton, $145, Money order 
or certified check. J. A.LaTorre, P. O, 

Box 521, Lawrence MA 01842. 

MOTOROLA P33-BAC 5W Hand! 
Talkie, excellent condition with an- 
tenna, mike f Ni-Cads, 34/94 and 
94/94 - $95; Heath HX 20 8a 10 
meter SSB and CW transmitter, HR-20 
80-10 meter SSB, CW, and AM re- 
ceiver, and HP- 20 AC power supply, 
good condition — $195. FOB, 
W5PNY, 25G6-A, 35th St., Los 
Alamos NM 87544. 



12 



73 MAGAZINE 



Recently a number of GE Pocket Mates 
have become available, and they make 
ideal walkie-talkies for 2 meter FftL They 
have several advantages: 1) small size, 2) 
extremely sensitive receivers (.3— .4 jiV for 
20 dB quieting, 3) good output (1W), and 4) 
reasonable price. 

These units are a good buy provided you 
make sure of several things first. If all of 
these requirements are met, then you will be 
making a good investment: 

Make sure the unit is dual channel (if you 
want it) and check for Vi-lW output. Check 
for 1 fiV sensitivity and make sure the 
speaker is good, because it doubles as the 
microphone. The unit should squelch at a 
setting between 2 and 5 on the squelch 
control The antenna should telescope pro- 
perly and no corrosion should be present in 
the battery compartment. Check the opera- 
ting frequency with a counter; if it is above 
160 MHz or so, some of the brass slugs will 
have to be replaced with green ferrite ones 
to lower the frequency ( It isn't a bad idea 
to get several extra green and yellow slugs 
anyway, since they are easy to break. ) 

To take the unit apart, first remove the 
screws holding the speaker and unsolder the 
wires. Then remove the 4 screws fastening 
the case to the antenna block. Next remove 
the small screw just inside the bottom 
(battery) plate. The chassis should then slide 

out. 

Using a tiny iron, unsolder the crystals 
and replace them with 2 meter ones (avail- 
able from KW Industries - they already have 
correlation data). It isn't a bad idea, either, 
to write GE and request a manual This 
makes it easier to find exactly where every- 
thing is. 

Now you are ready to tune it up. Tuning 
the transmitter is simple. Hook the two 
battery springs to a 14V power supply, with 
a 0—100 mA meter in series. Hang a 
47-52fl 1W resistor from the antenna jack 
to ground and tune T5-T10 for maximum 
current. Remove the resistor, extend the 
antenna, and peak L10 and LI 6 for maxi- 
mum output. Repeak all other coils again, 
and adjust the drive pots for 180-190 mA 
(change the meter to a 0- 1 amp one). T5 
and T6 put crystals Yj and Yj respectively, 
on frequency. When properly tuned, you 



Herman Cone WB4DBB/4 
Route 4 f Box 493D 
Chapel Hill NC 27514 



GETTING ON 



2m 




WITH 




OCKET 





OCTOBER 1973 



13 






SQUELCH MODULE 

■ ^ i — * 

7 



RECEIVER 
IF. 




RECEIVER 



RECErVER 
FRONT END 



RECEIVER 

CRYSTAL 

FILTER 



LOW LEVEL 

TRANSMITTER 

STAGES 



TRANSMITTER 
AUDIO MODULE 



DEVIATION 
CONTROL 



TRANSMITTER 



F\ DRIVE CONTROL 
F2 DRfVE CONTROL 



Transmitter Coils 

T5 — F1 osc, sets crystal (s) on frequency 

T6- F2osc. " 

T7, T8, T9 — dou biers — tune for max. current 

T10 — driver 

L10- P,A. tank 

L16 - P. A. output filter 

Tune T10, L10, L16 for max. output into 5212 

load. 

Receiver Front End Coils 

L2 — rf amp 

L4 f 5 — front end 

L6, L7 — mixer 

L10 — osc. coil (adjust first) 

RLVR 1-f Coils 

Leave these alone unless you are sure they are off, 
L25 - in filter 
L15 — coupling 
T1,T2-i-f coils 
T3 — discriminator 



Accessory Jack 

(Hole directly above jack is for external antenna.) 
Pin 1 ext. mic. 5 ext. squelch 

2 ext. mic. 6 not used 

3 13 to 15V 7 gnd. 

4 ext- PTT 

Receive Crystals (Sc - 18 holder) 



f c = 



fQ-10.7 



Coil Slug Color Codes 

Receiver: 

Yellow: L6, L15, L25 

Violet: L10 {Yellow Will Also Work) 

Green: L2, L4, L5, l_7 
Transmitter: 

Yellow: T5, T6, T7, T8 

Green: T9, T10, L10, L16 

Transmit Crystals (Sc - 18 holder) 

f =L° 

C 8 



Fig. I, Internal diagram and coil identification, 



should get around a watt out with 180-190 
mA drain. Some units have another pot on 
the transmitter audio board - adjust it for 
proper deviation. If yours doesn't have this, 
it is fixed at 5 kHz. To set the deviation on 
these units, find the wire going from the 
audio module to the transmitter's phase 
modulator. It will have a resistor of approxi- 
mately 1 MQ in series with it. Decreasing 
this value will increase deviation. Also, some 
units have only one drive control, which 
controls both frequencies. My own is de- 
signed this way. 

The receiver is a little more difficult to 
align, but good results can be obtained if 
you have a good signal to work with. It is 
best to use a signal generator set exactly on 
your receiver's frequency. In most cases, the 
front end board is the only one that should 
be touched. 




A view of the unit with its case removed. 



14 



73 MAGAZINE 




KING 



Your finest discount antenna supplier 

Beat inflation. 

Save time and money with mail order. 

• NAME BRANDS • 

Gigantic Savings 

FREIGHT PREPAID MOST ORDERS 
48 HOUR SHIPMENT WITH CASHIERS CHECK OR MONEY ORDER 



ROTORS 



ANTENNAS 



TOWERS 



ACCESSORIES 



ANTENNA KING 

Box A, Lomita, Calif. 90717, Phone (213) 534-"KING 



JUMPER 




ORANGE WIRES 

(15 K RESISTOR JS 
ATTACHED TO ONE) 



Fig. 2. Rear view of the speaker* Add a wire from 
the jumper to the chassis to insure a good ground 
connection. Carefully covering the open areas with 
tape gives an improved audio response. 

First, feed a strong signal (30-300 juV if 
you have a generator) Into the antenna and 
adjust L10 until the crystal "pops" into 
oscillation. This is a fairly critical adjustment 
and a change in noise level will be heard. 
Then adjust all other coils on this board for 
maximum quieting, reducing the input signal 
as you go. It should be fairly easy to get a 
sensitivity of less than .5 /iV for 20 dB of 
quieting. The filter and i-f boards are pro- 
bably in reasonably good alignment already, 
and shouldn't have to be touched. 

When adjusting the various coils, it is 
advisable to first melt the wax (if there is 
any) with a warm screwdriver blade, and to 




PIN 3 

PIN7 



Fig. 3. Schematic of a battery charger suitable for 
charging the Pocket Mate's Nicads. Starting at 
maximum resistance on Rl, adjust the setting for a 
meter reading of 15 mA and charge the unit for 
10-16 hours. 

tune them with a flat toothpick, since the 
slugs are very fragile. Check to see that the 
coils have the appropriate color-coded slugs, 
since they are made of different material A 
vast improvement in audio quality can be 
had by carefully covering the back of the 
speaker with masking tape — this is es- 
pecially noticeable when transmitting. 
Mallory TR-136 mercury batteries (8.2V) 
work fine in the Pocket Mate, but for 
long-term economic feasibility suitable 
Nicads can be obtained from Alexander 
Battery Co., Box 1645, Mason City, Iowa 

50401. 

. . .WB4DBB 




OCTOBER 1973 



15 



— 






YAESU 



SF101 P $59 00 
5P10I 1900 



FviQl S« 00 
16QM tHHOUGw 1 



FT 101 f«49 00 



FL7IO0 Ui» 00 
ijudw iff 







FT0K401 SS94 00 
THANSCVR S*Ort PEP 



FV401 J99 00 
EXTERNAL VPO 

THROUGH 10M 



FL 70006 SJMOO 
LINEAR AMP 
1200W PCP 



I 



C 
P 



c v 





FRDA40G £299 00 

RECEIVER 

1A0M TMflOUGH I0M 



ftE3 n I 



FLOM400 S394 00 

EXCITER 

90M THROUGH HOM 



FL 20006 1399,00 
LINEAR AM* 
120CV- PEP 



FP2 

AC POWER 



SUPP1V 



■ 




FTZFEI S 279 00 
144 1*H4V 

ion HIGH tW LOW 




VCJBS O »tt 00 

DIGITAL COUNTER BLRLT IN PRESCALEH 




YOUR ASSURANCE OF PERFORMANCE & QUALITY 

The 5P1Q1 P Landhner provides phone patch operation as well as speaker. 
From panel. Patch twitch, meter, TX and RX gam controls. Rear apron: 
Receiver 4 ohm output, receiver 600 ohm output, monitor null switch, bal- 
ance control, line jack, transmitter high Z jack. 

The FV 101 permit* split frequency operation and control from either th* 
FT 101 or FTOX401. 

The FT 101 exciter coven 160, BO. 40. 20, 15, (CBh and 10 meters and 
comes complete with microphone cable and plug, fused DC power cable and 
plug, AC Cable with plugs and all necessary plugs are furnished- AC and OC 
supplies are internal. 

The FL 2100 Un*a' ampJifie* needs only 3 wire cable and coax cable, Con- 
nectors are furnished, 

FTdx40T features high power, super sensitivity and sharp selectivity. The FT 
dx401 includes: AC power supply, noise blanker, 100 KG and 25 KC cali- 
brators. VOX break in, phone patch terminal, coating Ian. Covers 3.S through 
10 MH; plus VWVV 560 watts PEP, AM that is required to gel on the air is a 
microphone and speaker. 

The FV 401 permits split Frequency ape-ration lor the DX chaser or net opet 
ator Covers 30 through 10 meters 

FL 2000 B 1200 wans PEP. 1000 watts CW. 600 watts AM. Drive power re- 
quired 100 watts. Has two cooling fans and uses two 572 B tubes, 

FRdx4O0 includes 2 mechanical filters plus "T" notch rejection tuning, ind 
c rentier lor easy lero set for SSS Crystal control 1st mixer and tunable 1st 
IF. provides stable operation and high spurious rejection, 100 KC and 2S KC 
calibrators. VFO can be used in transceivt operation in conjunction with F 
senes transmitter 

FLdx400 operates SSB, I USB LSB selectable), AM, CW and FSK Circuitry 
can be built in lor RTTV operation, 240 watts PEP VOX, PTT\ and break in 
CW 

FL 20008 grounded grid linear uses a utiir at 5?2 B tubes. Plate meter V$WR 
monitor, 2 fans, built m power supply, SO through 10 meters. 1200 watts PEP 
with distortion product in excess of 20 DB down. 

FP 2 AC power supply specifications Output 135 volts. 2 amps. AG input 100H 17/220/234 
vol is, Speaker 5" u 3-1/5", Portable or home bete operation can be achieved with the addition 
of the optional FP 2 power pack. This AC power pack provides regulated DC power for the 
transceiver and charging voltage tor optional leak proof rechargeable colloidal type batteries. 
In addition, a high fidelity elliptical style speaker is built mlo the pack. 

The FT 2F8 Opens the door to noise free broadcast quality 2 meter operation, and thanks to the 
repeater stations throughout the country, the 2 meter band n no longer restricted to Fine of sight. 
General coverage 144 to 148 MHi. 12 channels 13 supplied? Push to talk Receiver 3 amps, 
transmit 17 amps, power source 13.5 volts + 10V Dimensions 6-3/8" w, u 2 1/2" h a 10" d . 
weight 4 lbs. Comes with dynamic microphone, connector plug, DC cord, fuse and mobile 
maun! 

Th« FT 2 auto is a compact base or mobile VHF/FM transceiver, covering 146 to 148 MHt, 
featuring electronic scanning up to 8 stations between 146 148 MHi with priority channel sam 
pling while locked on another channel. Adjustable lone burst push-button lock on lor repeater 
actuation The FT 2 auto ♦$ self contained. Two power cables are supplied with ihe transceiver, 
including all mounting hardware, cables, connectors, and accessories required for both mobile 
and base installation, as well as dynamic push to talk microphone. Operates from various AC 
voltages or 13 5 DC, Dimensions 8-3/4" m, m *1/4" h. n 115/8" d Weight 9 ibv 



5P401 P »9« 
5P401 19.00 

SPEAKEH'PATCH 





f - i € t 




FT? AUTO $379 00 
1*4 U 




Cpmpltti With 

AC Pa*r Cold 6 Ft 
OCPmhi Cord 6 Fl 
Stfirui Tm L«d with 
&NC Conn«cior 3 Fl 



SPECIFICATIONS 



Enqurrev r^ngi 



Actu'*^* 



Oiii]4iv 



S-l*np1ir>B him 



'HO**> ttrrn 



rttoutney Urwl 



Q'Ullw 



Input VoHt 



vc.ttW 



SHi to ,1TjMHi iSOHr Ki 20OMH/I 



*1>ffH frM* mlfrMy * t CiHint 



h Di^l 



1 mdli 



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7 1*£ 



kUi MW, 



Onotjty tub# 



20m V— ?0Vpp 



MAX Input VoUjis 



ryot Imydanci 






Ll 



Si«eaiTv 



Po*pr 

Require 

nvioti 



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VC J«ap" 



eoVfm in 

iSV p pj 



HIGH T W enhrn Low 5€ ohmi 



Leu Ihaw fQpf 



' ',' H; £>»-/ irAi'iT** 



0005'. 
0025*- if 



«1 »«C 

ffi - UPC 



WOl 1 10/ If 7 * 2O0/?2O 733V 
5Q/60H; 1BV A 



Jl^U^^^A^ 



rt^ehx 



Tub* 



D'iDllv lutw 



tOttduClDfl 



Sil"tiK> diode 



$4litt>n Ti»nu«t»- 



FET 



IC 



VC 3550 



J2Oirt»X»OfHjK270lOI 

i 8 14 W X 3 1/4 H 10 \tl i«hm 



12 



26 



PFttCES SUBJECT fOCHANtlE WITHOUT NQTJCE 



FACTORY SERVICE IS AVAILABLE WHERE WARRANTY HAS EXPIRED. NIK- 160 (J60M)KIT 
tl€ 00 WITH XTAL PLUS LABOR, MODERNIZATION KIT MIR- 1 FOR OLDER MODEL FT101 
t 70.00 FACTORY INSTALLATION ONLY. 



HAM RADIO CENTER 

8347CH'VE flLVD ST LOUIS MO &3U2 



ADIRONDACK RADIO SUPPLY 

IBS 191 W MAIN ST . AMSTERDAM MY 12020 



ItfAafTflONlCS AMATEUft El f CTRQNIC SUPPLY 

4033 BHOWIMSV1LLE flD . TREvOSE PA 19047 fi?1 COMMOMWEALTH AVE , fi. 32^03 



EKTER RADIO 
3Q02E ASHLASt FRESNO CA 93776 



HEMRV RADIO STORES 

Lc» Angvlri. Anahtirn, C-Ai 
MAM RADIO OUTLET 
aurhrvBJfnr CjI 

GHAHAM ELECTHOHICS RACQM ELECTRONICS 

*33S PCMMSVLVANIA. UNDF AMAPDL^S ID 4G204 R»nlo*r W«h 






FfttfCK RADIO BV SUPPLY / ^0* 2&4 95&1 
HutlT- Md. Aihtmllp. KC 

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Fi'mmgdlU L.I V«ll«v Sl»MIH. L I N«W York 



WILSON ELECTRONICS 
Win mm N*« 

ED JUCE EtECTRONiCS 

Poil Worth. T«m 
AMATEUR ELECTRONICS SUPP1V 

M>^iuk». Wn CL«*4*r>0. Ohm 



W YAESU MUSEN USA INC. 



TWX 910 346 7624 
TEL 213 6334007 



VAtSU 

V 



7625 E. ROSECRANS AVE UNIT 29 PARAMOUNT, CAL. 90723 



Silas S. Smith WA9VFG 
2308 McCord 

Murphysboro IL 62966 



FR 




EQU 



MICROWAVE 




MEASURING 

AT 
QUENC 





This article is not intended to give the 
theory, but rather a practical solution 
to the building and use of wavemeters at 
microwave frequencies. 

In microwave work, frequency is one of 
the most important measurements. It must 
be understood the wave length in the devices 
described here is not the exact frequency 
wave length. A well-constructed wavemeter 
that has been calibrated can be very precise. 
They can be within 1.5 MHz at 10 GHz or 
less than half of a MHz at 1250 MHz. 
Temperature has some effect on the frequen- 
cy. Most commercial wavemeters are con- 
structed of Invar, a metal that changes very 
little with temperature. Some parts are of 



7 



SOURCE 




WAVEMETER 



INDICATOR 



B 





i 



LOAD 



WAVEMETER 



SOURCE 



rfis 



= LOAD 



INDICATOR 



ATTENUATOR 




WAVEMETER 





POWER 
INDICATOR 



WAVEMETER 



f LOAD OR LOSSY MATERIAL 
WITHIN CAVITY 
OR NOTHING 
AT LOW POWER 



Fig. 1. 



bi-metal construction to compensate for 
temperature. For the average experimenter, 
brass and copper will have to suffice. Al- 
though silver plating is desirable, it isn't an 
absolute necessity. Frequency at microwave 
frequencies can be measured by three meth- 
ods: wavemeters, slotted lines, and frequen- 
cy comparisons. All of these methods are 
used commercially. The frequency compari- 
son is usually used in the laboratory to 
calibrate the wavemeter and the slotted line. 
As a general rule, any method of frequency 
measurement used at lower frequencies can 
also be used at the microwave frequencies, 
but are not always practical. The resonate 
cavity as a wavemeter is used in microwave 
measurements. 

There are three types of cavity wave- 
meters: the transmission type, Fig. 1A and 
IB, the reaction type, Fig. 1C, and the 
assorption or absorption type, Fig, ID. All 
are resonate cavities. The way in which the 
wavemeter is used determines the type. 

All wavemeters are adjusted for maxi- 
mum readings except the assorption type. 
The assorption is adjusted for a dip in power 
output, The most popular wavemeter used 
by the beginner is the open circuited trans- 
mission line type, Fig. 2. This type of 
wavemeter is the equivalent of lecher wires, 
(Open circuit refers to the standing wave 
within the cavity, not the physical construc- 
tion except as it pertains to the frequency 
wave length.) The practical physical dimen- 



OCTOBER 1973 



17 




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144-148 MHz 



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Fig, 2. 



sions are not many. The inner circumference 
of the main tube should be less than one 
wave length at the highest frequency to be 
measured. The rod should be small com- 
pared to the tube. If inductive coupling is 
used, the inductive coupling should be close 
to the shorted end. For probe coupling, the 
probe should be close to the middle. The 
open circuited transmission line is generally 
used in two ways. This type can be used "in 
line' (Fig, IB) as it has very little loss when 
it is resonated. However, it should be re- 
moved from the line before transmitting, as 
it will act as a narrow band filter. The half 
wave length is the measurement between the 
two successive points at which the generator 
will load to maximum, as the rod is inserted 
or withdrawn. 

Another method in the use of the open 
circuited transmission tine calls for the use 
of an additional circuit, as in Fig. 3. The 
circuit is a simple crystal diode detector 
connected to a microampmeter. The diode 
and condenser are usually built into the 
connector, as the leads should be kept as 
short as possible* The half wave length 
measurement is made on the rod between 
two successive maximum readings on the 
meter, as the rod is inserted or withdrawn- 
See Fig. 1A and IB for the setup. 



CRYSTAL 
DIODE 




MICROAMMETER 



DH* 



t 



/j\C 



R 




Fig. 3, 

The quarter wave coaxial cavity is actual- 
ly a shorted coaxial line one quarter wave 
length long (Fig. 4, 5, 6), As illustrated in 
these figures this type makes a very good 
cavity to use as a standard. To calibrate, a 
chart is made of the micrometer settings at 
different frequency wave lengths from a 



18 



73 MAGAZINE 



calibrated source generator. Don't tell them 
so, but the Public Relations Department of 
the Telephone Company may help you here, 
if they have any microwave technicians close 
by. The quarter wave coaxial cavity can be 
either physically open or closed. If closed, 
the closed end should extend at least a 
quarter of an inch beyond the center con- 
ductor at its lowest frequency. The closing 
of the end will lower the resonate frequency. 
Probe (capacitance) coupling as used for 
coupling in Fig. 5 will shorten the center 
conductor, and loop (inductive) as used in 
Fig. 4 will lengthen the conductor. In Fig. 4 
we change the length of the center conduc- 
tor to change its one quarter wave length. In 
Figs. 5 and 6 the center conductor remains 
the same, and we change the resonate 
frequency by capacitance. This method 
makes it necessary to construct the center 
conductor very short as compared to the full 
quarter wave length as in Fig. 4. These 
devices are not longer, so caution must be 
used when calibrating. The closed wavemeter 
as indicated in Fig. 7 is a shorted coax line at 
each end. The wavemeter uses a shorting 
plunger which is movable along part of its 
length. If used as the quarter wave coaxial 
cavity, the center conductor must be longer 
than a quarter wave length. 

Up to this point we have covered most of 
the wavemeters that could be used from 
around 144 MHz up to approximately 3000 
MHz. 1000 MHz to 3000 MHz are usually 
called the lower microwave frequencies. If 
the inner circumference of the outer tube is 
kept less than one wavelength, these wave* 
meters will operate in the desired TM mode. 

There are four ways to couple energy into 
a wavemeter, loop (Fig. 4), probe (Fig. 5), 
direct (Fig. 6) and slit (Fig. 8). The most 
commonly used is the loop, as it has very 
little effect upon the electric field. The usual 
methods for changing loop coupling is to 
change the size and orientation of the loop. 
Loop coupling is usually placed in the high 
current area of the wavemeter. Capacitative 
coupling is changed by the size of probe and 
the distance from the center conductor. 
Capacitative coupling is usually placed at the 
high voltage portion of the wavemeter. As in 
Fig. 5, a small probe - say Vi in. piece of No. 





Fig. 4. 



Fig. 5. 



22 wire, for example - may require an 
external voltage amplifier. The smaller the 
probe, the less effect on the resonate fre- 
quency of the wavemeter. In direct coupling 
as in Fig. 6 the primary concern is imped- 
ance. To increase the impedance, move the 
coupling up the line away from the shorted 
end. To decrease the impedance, move the 
coupling down the line toward the shorted 
end. Slit coupling (Fig. 8) can be a small 
hole or a series of small holes or a slit. Its 
purpose is to allow a certain amount of 
leakage. In all forms of coupling, it is 
desirable to use loose coupling, as the 
wavemeter will have less effect on the 
system, and the Q of the circuit will be 
higher. 





Fig. 6. 



Fig. 7. 



Above 3000 MHz, usually only the 
tunable wavemeter is used. The cavity is one 
quarter wave length long. The cavity can be 
coupled in three ways: loop, probe and slit. 
Because of the high frequencies, the slit is 
usually used, and the meter is most often 



OCTOBER 1973 



19 





Fig. S. 

kept as an assorption meter. In the assorp- 
tion method, the wavemeter should be de- 
tuned when not in use. Some of the cavity 
wavemeters have a little lossy material added 
to absorb some of the energy, as in Fig. 7. 
Lossy material can be made from graphite 
impregnated cloth in epoxy* 

There is one other type of wavemeter 
thai can he briefly mentioned; it is the 
reference wavemeter. The reference wave- 
meter is of any design as described, but 
would be constructed more like Fig. 6. II 
can be locked when adjusted to a selected 
frequency and used as a reference standard. 
The micrometer assemblies can be made 
from any micrometer with additional parts 
welded on. I constructed one using an 
oversized tube over the main cavity, and 
dimpled it at various places around its 
circumference until it fit smoothly over the 
cavity, and 1 used a piece of 3/8 threaded 
brass pipe as the main adjusting screw. I am 
sure you can come up with a good one 
without any backlash. This wavemeter 
spread the 1250 MH2 band out to over 100 
inches by rough measurements, 1 haven'l 
calibrated it> so I can't say for sure just how 
far. There are three nice veeder root count- 
ers in the APX 6 which would make ex- 
cellent wavemeters plus sliding contact ma- 
terial- One could even use the entire cavity. 

The last method of microwave measure- 
ment that we will look at is the slotted line 




Fig. 9 



(Fig. 9). The slotted line is a section of coax 
line along which is cut a slot. A probe, which 
is a simple crystal detector with a one 
quarter wave length shorted stub for a dc 
re'turn path, is moved along near the center 
conductor of the slotted section. In this case 
we are looking for two successive minimum 
readings along the line. The distance be- 
tween these readings is one half wave length, 
A slotted line should also be calib rated. If 
calibrated at one spot near the intended 
frequency to be measured, a chart will not 
have to be made -just a K factor obtained. 
The distance between two successive read- 
ings times the K factor should equal the 
frequency half wave length. There are a few 
accessories that can be either built in or used 




Fig, 10 

externally. One is a coax attenuator shown 
in Fig. 4. It will slide in and out of the other 
half. It too can be calibrated if one wishes. A 
5 OH resistor can be used for an impedance 
match for 5012 lines if inductive coupling is 
used such as in Fig. 10 and when the loop is 




Fig. 1 1 - 

small. The line stretcher (Fig. 11) is useful 
with the slotted line. It merely consists of 
two coax sections, one sliding into the other. 

• . .WA9VFG 



20 



73 MAGAZINE 



Bill Hoimngton Kl CLL 
Farover Farm 
Peterborough NH 03458 










Fig. 1. Build a complete receiver front end 
with the RCA CA3102E integrated circuit. 






Truly it is said, "Nothing succeeds like 
success/' and the RCA lads in Somer- 
ville NJ are to be congratulated on this latest 
achievement of theirs in building an IC 
which works well as a complete 2 meter 
front end in corpora ting rf stage, mixer and 
oscillator. 

This article concerns the RCA IC 
CA3102E in a 14 pin in-line case which 
contains six 1000 MHz semiconductors. Bear 
in mind, please, there is a large difference 
between integrated circuits for digital work 
and those for rf work. 

This article, like most of mine* is not just 
a construction article. It deals with the 
design and philosophy of the components 
and the circuits shown because I believe 
amateurs should have the opportunity — if 
they wish — to learn as much as possible 
while building. There is a perfectly valid 
philosophy which concerns "Connect a short 
red wire between point A and point B." 1 
have done lots of these myself, but always 
found I had to force myself to forget all I 
knew about radios and become a true 
know-nothing while doing it. 

The RCACA3102E 

This little gem has two independent 
differential amplifiers inside, with its sche- 
matic shown in Fig. 1. Each of the six 
transistors has an Ft in excess of 1 GHz, 
making this IC useful to 500 MHz. Special 
care has been taken in the internal chip 



layout to assure good freedom from reaction 
between the two independent amplifiers. 
Inasmuch as I seldom write about anything I 
have not tried out, 1 have some running here 
and they work well. 

Since the true home -brewer is always 
interested in possible applications of what he 
spends his hard-earned money on, the 



I — vw 



o + 



RF IN> 



+ 12 





-^ tf* > RF OUT 



+ O 



Fig. 2. Differential amplifier connection, RCA 
CA3102E (pin view). See Figs. 3 & 4 for represent- 
ative values. 



OCTOBER 1973 



21 






RF IN > 



0+ 12 



+ 12 O^^WV 





C4 
-^^- > RF OUT 



Fig. 3. Cascade connections, CA3102E. For tuned 
circuit values, see LI in Fig. 4. 



following list of CA3102E uses is included: 
VHF amplifiers , mixers, multifunction com- 
binations such as rf/mixer/oscillator, con- 
verter/i-f, cascode amplifiers for i-f, or dif 
amps, product detectors, doubly-balanced 
modulators, balanced quadrature detectors, 
cascade limiters, synchronous detectors, 
balanced mixers, synthesizers, balanced cas- 
code amplifiers, sense amplifiers (whew!i 
and others. The age of the VHF-UHF ICs is 
being opened up by these I GHz beauties. 

Dif Amp and Cascode Details 

Inasmuch as the LC is formed by a 
cascode amplifier, and the mixer section has 
an rf amplifier in it, a few words on the use 
of this chip in both modes is timely. Figure 
2 shows one half of this versatile little chip 
of 1 GHz capability in the dif amp mode, 
where Ql is a grounded collector amp 
driving Q2„ a common base amplifier, Q3 
acts as a constant-current source. This is the 
configuration that is best if strong signals are 
present, as in metropolitan areas, or other 
areas where amateurs may be in close proxi- 
mity to each other. This dif amp mode has 



slightly less gain than the cascode mode, but 
this need not be considered unless you are 
trying to minimize components, often a false 
concept. Two stages with lower gain, such as 
dif amps, are often much better and easier as 
well to build and line up then one of higher 
gain. Noise figure goes down with current, 
another reason for two stages. 

Circuit 

Referring to Fig. 2, the rf arrives at the 
tuned circuit L1-C2 from the input matching 
capacitor CI. A tap about one turn from the 
ground end goes to the base of Ql, a 
common collector amp. Ql is emitter- 
coupled to Q2, a grounded base amp whose 
collector circuit has C3 and L3 for tuning. 
See rf section for details and component 
values. 

Constant-current Source 

The makers of these IC rf circuits use a 
lot of transistors in these tiny chips for this 
sort of thing. Making them mainly for 
commercial users, they put in, for example, 
Q3 ? which does not appear to do anything at 
all. It does however do nice things if you 
look a little deeper. When the temperature 
varies it tends to maintain a constant current 
on the amplifier and therefore lessens any 
detuning effect that might otherwise occur 
and other nuisance effects. Just use it as 
shown. It helps for a better circuit, especial- 
ly when you can take it out in your car in 
the winter right out of a heated room or 
garage. After all, it only costs the maker a 
fraction of a cent to photograph it in there, 
so why should you worry? 

Cascode Connection 

Figure 3 shows connections for the cas- 
code configuration, which has the highest 
gain but cannot handle strong signals like the 
dif amp. The rf goes through the series 
matching cap CI (referring to Fig, 3), then 
to the tuned circuit L1-C2 and then to the 
low impedance base of Q3, a grounded 
emitter stage. This stage is cascode coupled 
to the emitter of Ql, and the signal goes out 
on the collector to the tuned output circuit 
C3-L2 and on out through C4. Q2 is not 
used in this mode, and simply floats for dc, 
with external connections 4 and 14 bypassed 



22 



73 MAGAZINE 



to ground for stability purposes. Keep LI 
away from L2, and use a shield between 
them if needed. Put the shield more or less 
in line with pins 5 and 1 2, as shown in Fig. 
3. More details in the rf section. 

Internal Feedback and Stability 

The compound (internally connected dif 
amp or cascode) connections of the dif amp 
or cascode are both much better for internal 
feedback (having less) than a single grounded 
emitter transistor, with the best in this 
respect being the cascode mode. The ratio of 
how much better may be as high as 1/140 at 
low frequencies, to perhaps 1/10 at 100 
MHz. In the cascode circuit this may be as 
high as 1/135 to 1/1200. In any case the 
internal feedback is low enough so that no 
consideration of neutralization is needed. 
This reverse transconductance is sometimes 
labeled Yr, in case you should meet it some 
dark night. Just be sufe the external feed- 
back does not clobber the nice internal 
feature. Pay attention to the details and 
notes in this article and it won't (shielding, 
bypassing, etc.). 



+ 12 



AGC 



i 



The mixer gain can be easily controlled to 
a high degree in these versatile chips, up to 
60 dB or more, by putting a negative voltage 
on the base circuit of Q 1 in the mixer circuit 
of Fig. 5. Remove R3 and put the negative 
going age voltage on the base at that point. 
You will more likely use the age on the rf 
amp, though- In that case the age voltage 
would be applied to the base return of Q3 
through LI in Fig. 3. A good balance of rf 
amp current (minimize) and gain, as well as 
mixer gain, should be sought. 

Mixer 

Figure 4 shows the half of the CA3102E 
used as an rf amp, mixer, and L.O, buffer- 
amplifier. Note the grounded line between 
pins 5 an4 12. I am not quite sure how this 
is physically arrived at inside on that tiny 
chip, and it will have to wait for my next 
visit to Somerville NJ (RCA Solid State Hq), 
but it works fine. You would have to have a 
good microscope to find it! Ql is a grounded 
emitter rf amplifier which takes the rf signal 
at 147 MHz in on LI and direct couples it to 



0+12 




+ I20 



RF IN 
14? MNz 
> 



A 
UO. IN 

FROM osa 

SECTION 
136 MHz 




Fig. 4. One-half of CA3102E - use as a complete rf 
front end. Ll f 5 turns No. 20, 12mm long, 8mm 
diameter. Input tap at I, output tap at IJS. L2, 15 
turns No. 20, closewound 10mm diameter, L3 t 2 
turns over bottom of L2. 



Q2 } a grounded base mixer stage, Q2's 
collector goes out at 10.7 MHz to the i-f 
output transformer L2, link coupled by L3, 
to the output cable. Q3 is used as a buffer 
amplifier for the L.O, — the 136 MHz injec- 
tion voltage coming from the other half of 
the CA3102E used as the crystal oscillator. 
This section is quite straightforward even 
though an rf amp and buffer-amp for the 
L.O. are included, and works well due to the 
1 GHz transistors used. I checked it several 
times against a good 3N200 FET mixer and 
local oscillator chain, and it has a dB or so 
better sensitivity, or I should say conversion 
gain, than the FET job. 

Noise Figure 

The noise figure of the CA3102E used as 
an rf amplifier is highly dependent on 



OCTOBER 1973 



23 



— m 



current, as indeed in most semiconductors, 2 
or even 1 mA being good figures for rf amps. 
This noise figure runs about 4.6 dB at 200 
MHz for the transistors used in the 
CA3102E, 

There is a fairly simple rule to follow 
with these units, as already mentioned. Use 
of the lowest possible total current through 
QTs emitter will in general give the lowest 
noise figure. This refers to the use of the 
CA3102E as rf amps also. Note the setup for 
tuning LI, the series cap bringing in the rf 
and the two tie-points serving as output 
connectors. This method has proven to be 
very efficient, both for building the first 
model and for layout of the PC boards later. 
If done correctly, each tie-point can serve as 
a place to drill the PC board for a lead hole, 
or component tie-in. It is particularly impor- 
tant in VHF and more and more so as you 
go up into 220 and 450 MHz, to furnish a 
layout man with exact placement detail. 
You can no longer leave it to him, at VHF 
and UHF, unless he knows a lot about rf 

work and particularly the IC under consider- 
ation. You should think this out carefully, as 
VHF and UHF IC's handle quite differently 
than af, digital, or control circuits. 





m 




0+12 



m 



Fig. 5. Example of base bias in the CA3102E. 



Base Bias 

Due to the direct coupling of the various 
transistors, placing them in series dc-wise, 
attention should be paid to the base bias 
voltages, While in general the resistors may 
be as in Fig. 5, these should really be 
adjusted with signals flowing through for 
checking best noise figure, gain and current- 
I have already done this for you, but it is a 



24 



11 



My name is John (WB2AZT), and I'm the 
Amateur Products Manager for Venus 
Sclent if ic. By • now s you've probably 
scanned pur ad on the opposite page* 
you react as most haras do> you* re 
probably thinking, "That's a nice look** 
ing package, but who and what is 
Venus Scientific?** 

That's the purpose of this message—to 
acquaint you with our company, Its 
products, and its reputation. 
There's nothing like knowing that a 
manufacturer is able to back up his 
product claims* 

Basically, Venus Scientific is one of 
the country's leading manufacturers of 
electronic high voltage control systems 
for military and industrial applica- 
tions. Our H*V, Power supplies, were 
used with television cameras on the 

Apollo flights that sent TV pictures 
back from the moon* Some time ago, a 
group of us within the company who are 
all active hams, began pressuring our 
boss Fil Galluppi to let us get into 
the amateur radio market* After con- 
siderable urging and coaxing* including 
actually dragging him to several ham- 
fests, he too got the bug and gave us 
a go-ahead . 

So here we are with our first of many 
products we've planned for the amateur 
market- Our slo-sean monitor is in 
production, ready for delivery, and 
frankly, it's something : else again. 
More than Just an S.S.T.V. monitor, a 
flip of the switch converts the unit 
to the incredible Accu Syno™, an 
oscilloscope that clearly reads out 
both incoming and outgoing 5.3*1- V* 
signals- Other features, like our mas- 
ter G10 , -P.C-. Board, make the SS2 
flexible and long lasting* The specs 
on the next page are just a few of the 
features of the SS2. 






Just remember that the ten years we've 
been in business designing and manu- 
facturing high reliability systems has 
brought to the ham market the quality 
product I think we, as hams are en-. 
titled to* OK t now you know a little 
&bout Venus Scientific. Look for our 
ads in the months ahead and let us 
know what you think of our product. 

And by the way, in case you r re wonder- 
ing/ Yes, we'll announce our companion 
camera in the next few months. 






John Lot it o 
WB3AZT 



.-. . •'•;■• ■ • 









. .: 





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■i 



mm 



good thing to iearn about. There is also quite 
naturally a certain amount of interplay 
between Rl, R3, R6 and the current con- 
trolling emitter resistor R5. The optimum 
values are not critical or touchy, but will be 
seen to be quite responsive to best values. I 
generally use a 5K pot at the Rl , R3 and R6 
places to start off with, and a IK pot as R5, 
The proper values are soon determined with 
that arrangement, and you are not left 
guessing if you have the right values or not. 
Remember that monolithic photo-built tran- 
sistors have quite a wide range of parameters 
at times. 

Naturally I ran the mixer when finished, 
with an outboard oscillator as well as the 
internal one, to see if there was any reaction 
between the two halves of the CA3102E 
when used as rf, mixer and oscillator, but 
could not find any. It seems to be a 
"natural." 



■i 



7-100 pF 

TWEAKER 
ARCO 423 



■i 




TUNE TO 
136 MHi 



C£ 
5-80 pF 
ARCO 46£ 

Jfi* > TO MIXER 

1 (PIN 7 t 

01 OTHER HALF) 



+ 12 



Fig. 6. Interna/ schematic, H RCA CA3102E, IC 
used in the cascode connection as a crystal 
oscillator. LI, 5 turns No, 20, 12mm long, 8mm 
diameter. Crystal tap at 1 tectums, output tap at 1 
*£ turns. 



I have recently developed an IC tuneable, 
LO.j which also goes very well with this 
unit. Disable the internal L.O. by pulling out 
the crystal, and plug in the external vfo 

cable to pin 8, the base input of Q3. The 
unit was described in the July 1973 issue of 
73 Magazine, 



A. 



B. 



a 




Fig. 7. 136 MHz crystal operation. 



Crystal Oscillator on 136 Direct 

Referring to Fig. 6, we see the rf signal 
from the crystal entering Ql at the base, Ql 
is the grounded emitter portion of the 
cascode amplifier forming the oscillator. 
Note the crystal used is cut for 136 MHz 
direct, without multiplication of any kind. 
Some have expressed surprise at this, but it 
should be known that today control crystals 
are available up to 250 MHz direct, not only 
for two meters. Such crystals are commonly 
referred to as *' overtone," which to my mind 
smacks of obscurantism, the real functioning 
of that precious little piece of "glass" being 
as shown in Fig, 7. This gives you a rough 
idea of what is going on inside that little tin 
can. You can also see that only odd numbers 
can be used- If you try to use the even 
number combination in Fig. 7C, you will of 
course get no ac out of it. Never forget that 



26 



73 MAGAZINE 



INPUT 




SH5. GEN. 
INPUT 



C 



7,5cm 
STRAP 



10 cm 
BOX 



IN295 
DIODE 



r>h 




^^ 25 pF 



d-ce 



ADAPTER 

r)\> J AF OUT 

l — i ] DC OUT 



V. 



INSULATED WIRE 




Fig. 8. Oscillator frequency check-out circuit. 



a crystal operates on sound waves and that 
only certain numbers can be used. If this 
sounds to you like quantum mechanics, 
good for you, you're getting warm! A 
piezo-electric chip, if cut right, gives off 
electricity, positive on one side and negative 
on the other when compressed, and that is 
good old dc if you hold it that way! Madame 
Curie's brother used to demonstrate this 
nearly one hundred years ago by hitting a 
piece with a hammer and demonstrating to 
the entire hall a spark therefrom. What you 
need first is that the oscillator be running, 
and if it's a good oscillator, it will be as soon 
as you throw the switch. It has to run, it's a 
law of nature. So, as shown in Fig. 5, the 
oscillator voltage enters the base of Ql on 
pin 2, a grounded emitter amplifier. This is 
internally connected (direct coupled) to the 
emitter of Q2, a grounded base amplifier, 
the two-transistor compound forming a cas- 
code amplifier good to 450 MHz, Here it is 
used at 136 MHz. The output of Q2 goes to 
a tuned circuit Ll-Cl, tuned also to 136 
MHz. In this circuit, LI has two taps, one 
for the output going to C2, and then to the 
mixer in the other half of the IC The full 
gain of the cascode Ql and Q2 is used and 
needed, Crystals on 136 MHz are not to be 
taken lightly. They must be matched as to ac 
impedance fairly well into and out of the 
cascode. The input, base of Ql, is sort of a 



natural, as the base impedance is quite low 
and the matching can be helped by adjust- 
ment of both the base bias and the emitter 
bias, which I have done for you. 

The output match of Q2 into the crystal 
is done by tapping down on LI, and is also 
seen to be low in impedance. It is also 
possible to couple into the crystal by a two 
turn link, wound in the same direction as 
LI, and placed over or inside of LI. I 
generally tune up such an oscillator with a 
5K pot as R2, and another as R4, These are 
not at all touchy but you can make the 
oscillator run better that way. To check out 
and tune up — not only for frequency but 
also for good starting, absence of squegging,- 
noisy hysteresis jumps either in frequency or 
power and proper base biases — a tuned 
diode detector is very handy. A one or two 
turn link around the cold end of LI with a 
cable into a diode trough-line cavity does the 
trick. You must know if it is really on 136 
MHz. Figure 8 shows a helpful setup to do 
this. Set up the tuned diode detector and 
check for good, smooth, quiet power out, 
using both meter to measure and af to listen. 
Then bring in a wire, as shown, close to or 
around the diode tuner center conductor as 
shown in Fig. 8. Tuning the signal generator 
very slowly over the region 135 to 137 MHz, 
you should be able to hear the desired 
heterodyne resulting from the crystal oscilla- 
tor beating with the signal generator on 136 
MHz. If you do not, something of course is 
wrong. Do not, as I have said many times 
before, use a sensitive receiver for these 

Test operation should include good, clean 
tuning of CI (Fig, 6) with the oscillator 
coming on and off with a nice "plunk" in 
the af speaker indicated in Fig, 8. The meter 
should also come up and drop off with the 
proper action. Marginal operation is to be 
avoided like poison. For example, the oscil- 
lator may be just working, and the next time 
it won't come on at all. 

So there you are. If you build this IC 
front end as shown, it will work and in good 
style, I have done it here and it works fine. 
The operation is stable and secure not 
marginal. You can put any rf stage in front, 
or use another CA3 1 02E as the rf stage. 

. . .K. 1 CLL 



OCTOBER 1973 



27 



* Self-supporting With A TrUBander (A) 

* 32 1 - 40' - 48' - 56' 

* 3 Mounting Bases 

* Heavily Galvanized 



(A) Limited to JR TriBander, 
unless guyed, on 56* towers. 



32 FOOT 

TOWER 



II 



THE BEST 
TOWER 

VALUE!" 



ASPIRE CONSTRUCTION 



iruivft.N tftefM] 



Heavy steel ' 'beaded' 1 channel design for ex- 
ceptional strength -much stronger than tubular 
of same weight. "X" bracing & bridge type 
construction for exceptional torsional stability. 
Positive riveted construction & heavy galvaniz- 
ing makes it exceptionally durable for minimurtir 
maintainance. Tapering design provides 
"nesting" shipment at lower cost to you, as 
well as lighter sections as yog go higher, 
making it easier to erect, 

THREE BASES: Rigid concrete (recommended 

base is 3x3x3' in firm soil, 32/40' models, 

and 4 1 deep on 48/56' models. Hinged con- 
crete base provides option of lay-over, pro- 
viding you have suitable "gin-pole" and 
tackle facilities. And the EARTH ANCHOR 

base requires no concrete and holds well in 
firm {day, etc) soil and may be relocated 
later. 

A custom drilled rotor plate is provided that 
accepts all CDE rotors (AR22R, .TR44, 
HAM-M) and also the HY-GAIN 400 with slight 
enlargement of bolt holes. A friction thrust 
(lateral) bearing is included* 



u HI-SPIRE rr towers shipped 
truck collect from Indiana , 



TOWERS WITH RIGID CONCRETE BASE 

69C09K - . « . .32' 133 lb». $ 79*95 

69C09Z 40' 175 lbs >., 104.95 

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&9C100, M T H wrench to drive anchor! (8 Ibi.) ,«♦,.. 9,95 

Include! anchor bate and anchor! (anchor bases require no 
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The Best Ham Tower 
For 15 Years 

When you need "ham" gear & 
accessories call H.I. ! 

efCoBBtf 

fj industry 

CALL:Tues. /Sat.-Noon/5PM 
Al McMillan W0JJK 
(712) 323-0142 

WRITE: HOBBY INDUSTRY 

Box 864 

Council Bluffs, Iowa - 51501 



28 



73 MAGAZINE 



FJ. Bauer W6FP0 
P.O. Box 1086 
Feiton CA 95018 



INSTANT REPLAY 



FOR 



YOUR TAPE RECORDER 



At times a tape recorder can be a useful 
accessory to any amateur station. One 
obvious use is relaying information directly 
to another phone station on the net. Instead 
of laboriously repeating or paraphrasing the 
message, why not record it on tape and 
retransmit it to the other station? 

The simple control box described in this 
article makes this procedure a cinch. It has 
the following operating features: 

1. Off-the-air recording may be monitored 
on the receiver speaker or earphones at 
any audio level without affecting the 
recording level 

2. Recorder output may be monitored either 
for cuing in or transmitting purposes 




TO HEGH SIDE OF 
AUDIO GAIN POT 



MIC W/PTT 



6 6 MOM 



I TOR 



TRANSMITTER 



RECORDER 



TRANS 



MIKE 



MIC W/PTT 




RECEIVER 

"J 



TO HIGH SIDE OF 
AUDIO GAIN POT 



MONITOR 



Fig. 1. Tape recorder control box interconnec- 
tions — all cables are shielded. 



without tying up either the transmit or 
receive function, 

3. Recorder output is reduced to the same 
level as average microphone output during 
transmit so that it is unnecessary to 
readjust microphone gain when switching 
from microphone to recorder. 

4, No modification of the tape recorder or 
other equipment is required other than 
adding a short audio cable to the audio 
gain control of the receiver or transceiver. 
A block diagram of the setup is shown in 



IN-0U1 
J! 




si 

— o- 



REC 



■»*- 



;vr AUDIO 
J3 



RECORDER 

J2 




OUT 



TRANS 



Rl 
470K 



f— 3 



MON 



=LJ4 



MIKE 



MIC 



TAPE 




*R2 
33 



«1 



AUDIO J, 
PTT 






3 



MIC 
PLUG 
TO 
XMTR 



Fig. 2. Control box schematic. Value of R2 should 
be adjusted so that recorder output is approxi- 
mately the same as microphone output. 

Fig. 1 and the schematic diagram of the 
control box in Fig. 2. SI switches the 
recorder from receiver to transmitter, and S2 

switches the transmitter microphone input 
from microphone to recorder, as required. 
Resistors Rl and R2 form a voltage divider 
that drops the recorder output to approxi- 
mate microphone level. High impedance 
earphones are directly connected to the high 
side of the voltage divider for cuing in and 

monitoring purposes. 

Generally speaking, there are two types 

of tape recorder interconnections available. 



OCTOBER 1973 



29 



MM 



Most tape decks have separate inputs and 
outputs, but many of the older tape decks 
have only one connection which serves as 
both input and output, depending upon 
whether the recorder is in the **record" or 
"play" mode. 

If your recorder has an "in-out" termi- 
nus, switch SI must be operated along with 
the recorder when changing from "record" 
to "play". If your recorder has separate 
inputs and outputs switch SI should be left 
in the REC position at all times. The 
recorder will then always be properly con- 
nected when switching to "record" or 

"play" at the recorder. 

Monitoring while recording may be done 

conveniently by listening to the receiver 
speaker or earphones. On playback, the 
recorder is monitored with earphones con- 
nected directly to the recorder output. 

My unit was housed in an old meter case. 
This presents a pleasing appearance and also 
permits mounting the controls at a con- 
venient angle. The meter hole is covered by a 
small aluminum panel upon which the con- 
trol switches are mounted. The microphone 
and monitoring jacks are mounted in the 




2 - Meters . * * Need we say more ? 




DIVISION 



3050 Hempland Road 
Lancaster, Pennsylvania 17601 



meter case binding post holes after reaming 
them out to size. All other remaining cables 
and connectors are brought out on the rear 
of the meter case as shown in the photo- 
graph. 




Front and rear views of control box. Photo was 
taken before the "trans mike" cable and plug was 
installed through grommeL 






Wiring of course is simple and not critical, 
since this is only an audio switching device. 
However, make sure all connectors are pro- 
perly grounded to avoid hum problems, 

A gadget such as this ordinarily does not 
get much use around the station, but when it 
is needed it is a real operating convenience. 
It surely beats haywiring the tape recorder 
with clip leads and riding the gain, trying to 
maintain proper output level to the transmit- 
ter. There is no reason why this or a similar 
arrangement couldn't also be used for SSTV, 
CW f or RTTY. 

. . ,W6FPO 



30 



73 MAGAZINE 



John Schultz W2EEY 
1829 Cornelia St. 
Brooklyn NY 11227 



2 KW PEP 

BUILDING BLOCK LINEAR 

A simplified construction approach to homebrew 
a high power single or multiband linear. 



Many amateurs have undoubtedly shied 
away from the construction of a high 
power linear because they felt the cost or 
the mechanical work involved in building 
such a linear would not be justified. After I 
had built my first few linears, I would have 
tended to agree with this viewpoint. How- 
ever, after having built many more linears 
over the years — and of widely different 
types — I find that with a small amount of 
advance planning the construction of almost 
any power level linear for the HF bands can 
be attempted by the home brewer using 
relatively simple hand tools. I should say not 
only "attempted" by the home brewer, but 
attempted witn a very high probability of 
success. 

The amplifier described in this article is a 
particular case in point. It illustrates a 
particularly simple construction technique 
and illustrates more than just the construc- 
tion of a specific linear. By selection of the 
number and types of tubes used, an ampli- 
fier of anywhere from the 200 to 2000W 
PEP level can be constructed. The cost is 
very low on a watts to dollar ratio and can 
easily approach 20W of input power per 
dollar of material cost- 
Planning the Linear 

If one looks at the overall diagram of any 
linear, it presents a rather complex picture; 
that is, perhaps not so much in terms of 
electrical functions of the various parts but 
in terms of mechanical construction when 
one starts to consider in detail how the 
amplifier will be built and how to arrange all 
the components on a chassis, do the 



mechanical work to mount the various com- 
ponents, etc- It is usually at this point that 
the home brewer starts to falter and forget 
about the entire project as being too com- 
plex and, particularly, too risky. The risk 
factor comes into play since if one assembles 
all the necessary parts — tubes, cabinet, 
chassis, transformer, etc, and then the am- 
plifier project doesn't work out, one will be 
left with a fair amount of money expended 
for no real return. 

The risk in construction can be almost 
completely eliminated if one looks at the 
construction of the amplifier from a differ- 
ent point of view rather than as a complete 
whole. As shown in Fig. 1, the amplifier can 
really be considered to be made up of three 
main "sub-blocks" - a power supply, a pi- 
network output circuit and a sub-block 
containing the actual tube circuitry with the 
antenna switching. The power supply sub- 







RF 


IN 






\ 


i 


POWER 
SUPPLY 

AND 

FAN 




AMPLIFIER 
AND 

SWITCHING 




PI- NET 

CIRCUIT 










i 


F 







RF OUT 



Fig. I. Most grounded-grid linears can be visualized 
as consisting of three main constructional blocks. 



OCTOBER 1973 



31 



TOUCH- TONE DECODER 




Dual tone 
decoder decodes 
one Touch-Tone 
digit. 

Available for 1, 
2, 3, 4, 5, 6, 7, 
8, 9, #, * and 

other dual tones 
700-3000 Hz. 

Latch and reset 
c a p a b i I i t y 
built-in. 



• COR control built-in. 

• Relay output SPST y2-amp. 
■ Octal plug-in case. 

• Compact 1-%" square, 3" high. 

• Free descriptive brochure on request. 

T-2 Touch-Tone Decoder „. $39.95 PPD, 

Specify digit or tone frequencies. 

(Include sales tax in Calif.) 



EHGIN 

BOX 455, ESCONDIOO. CA 92025 



super sensitive 




START 
HEARING the 
WEAK ONES 




JAN EL makes a preamp tor improving the performance 
of almost any receiver. All are resistant to overload and 
fully diode protected. Top quality construction. 



APPLICATION 


MODEL 


FfteaueiHicv 


OSCAR VI 


3QPB 


29.5 MHz 


6 Meters 


50PB 


50 5 MHj 


2 Meters 


544PB 


144 MHi 


2 Meter FM 


147PB 


147 MHz 


220 MHi 


220PB 


220 MHz: 


Aircraft 


120PB 


] 08 140 MHi 


FM 


lOOPB 


BH 1U8 MHi 


TV 


TVPB 


Ch2 13 iSpscirvl 


Miuli B<jr>d 


1GQPB 


145 174MH* 


432 MHz 


432PA 


432 438 MH? 


440 ATV 


432PA T 


435 445 MHz 


450 FM 


432PA-F 


440-450 MHz 


UHF FM 


H32PA-U 


450-4 70 MHz 



PB models are only SI 9-95 and the 432 PA models are only $23.95. 
All are in aluminum cases, have BNC connectors (others available), 
require 12 vdc p and are postpaid and guaranteed. Specify model and 
frequency when ordering. Other models are available with AC power 
supply. Write for details. 

JANEL can also supply a wide variety of receiving equipment for 
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laboratories 



BOX 112, SUCCASUNNA r MJ 07876 
Telephone: 201-584-6521 




Top view of amplifier sub-chassis shows how tubes 
are circularly arranged around plate choke, 

block should really present no problem. Any 
number of power supply circuits are avail- 
able which have been thoroughly proven in 
operation and one can even purchase rela- 
tively inexpensive high power capacity 
power supplies on the surplus market or 
used equipment market. Any amateur 
should be capable of building a simple bridge 
type rectifier power supply. The pi-network 
output circuit sub-block should present even 
less of a problem. Pi-network circuits for 
single band or multiple band use using 
conventional components or using toroid 
coils have been thoroughly described in 
many handbooks and articles. With a bit of 
patience, anyone can find the correct tuning 
conditions and component values to use 
with a pi-network circuit on any given band. 
However, it is the tube circuitry or actual 
amplifier sub-block that is at the crux of the 
whole linear construction project both in an 
electrical and in a mechanical sense. If this 
sub-block can be electrically complete so 
that the only other electrical wiring that is 
necessary is the power supply and the 
pi-network circuitry and if this amplifier 
sub-block can be easy to construct, almost 
70 to 90% of the work in building a linear is 
done! Of course it will still take patience to 
complete the linear and to tune it s but one 
can then have confidence that the linear will 
work. To take a very conservative approach, 
one need invest initially only in the compo- 
nents necessary to build the amplifier sub- 
block without risking a total investment in 
all the linear components that might not be 
used should one decide to give up the 
project. 



32 



73 MAGAZINE 



A 6KD6 Amplifier Sub-Block 

This article describes in detail the con- 
struction of a linear amplifier sub-block 
designed for use with one to five 6KD6 
tubes. Other tubes can be used as well, using 
the same construction ideas. Five 6KD6 
tubes can provide a maximum input of 2 KW 
PEP on SSB. The rock-bottom price I could 
find for these tubes was $1,50 each. They 
are available new from almost any discount 
tube dealer for around $3,00 each. Wherever 
these tubes, or other TV sweep type tubes 
for use in a linear are purchased, be sure to 
obtain tubes of the same manufacture, This 
applies also in case a tube needs to be 
replaced. 

The question of distortion products 
might be raised when beginning to describe 
any linear amplifier using TV type sweep 
tubes. Rather than get involved in this 
subject, which is not the purpose of this 
article, it is sufficient to say that the linear 
described will have 3rd order intermodula- 
tion products of -25 to -30 dB. Also, the 
purpose of this article is not so much to 
emphasize the use of a particular tube type 
as to emphasize a particular construction 
technique. If extremely low intermodulation 
proudcts are an overriding consideration, 
one can easily use regular transmitting tubes 
in place of the 6KD6's* 572B's, for instance, 
would lend themselves nicely to the type of 
construction presented here. 

Sub-Block Circuitry 

If one extracts from a linear amplifier all 
the circuitry which can be combined to 
make it as complete as possible except for 
the power supply and output circuit, the 
result will be the circuit of Fig. 2. In this 
case, the antenna switching circuitry has 
been included in the sub-block. The antenna 
relay used is a triple pole type so it can also 
switch a 1 2V zener regulator in during 
transmit to bias the tubes properly. During 
receive the tubes are cut off by the higher 
unregulated bias voltage to prevent noise 
generation. The sub-block contains within 
itself all the external connections needed 
except the power line connection for the 
power supply (assuming the power supply 
will be in the same overall enclosure as the 



FEEDTHRU 




TO PIN 2 ANY TUBE (CATHODE) 



150 



r 

si 



-L20 
— ■♦■ — ■vw- 

i 47K 

T TJN34 



47K 
1N34 ** 



-• ALC OUT 



<k-VW 



* + 20V 



I 

±_5K ALC ADJ. I 

OPTIONAL CIRCUIT (ALC) 



Fig, 2. Amplifier sub-chassis diagram, Up to 5 
tubes can be wired in parallel Ll r L2 and L3 are 

discussed in text. 



amplifier). The pi-network output circuit 
need only be connected between the plate 
circuit and the feed-through insulator which 
connects to the antenna relay. The power 
supply requirements to the amplifier sub- 
block are: a high voltage from 800 to 900V 
(at 200 mA peak for each tube used), a 
filament voltage of 6,3V (at 2.8A for each 
tube used) and a bias voltage (unregulated) 
from -25 to -100V at 50 mA. The bias 
voltage is not critical as long as it is more 
than 25V so the tubes are completely cut-off 
during receive. The series resistor for the 
1 2V zener will have to be adjusted according 
to the bias voltage so that the zener regulates 
properly without undue heat dissipation. 
The above are the only external power 
supply requirements, for the antenna relay is 
powered by the bias supply line. A monitor- 
ing circuit for relative power output is 
included in the sub-block which would be 
used to drive a I mA meter via a 25K series 
connected variable resistor. These compo- 
nents would be mounted on the front panel 



OCTOBER 1973 



33 



of the overall linear enclosure. This meter 
plus an ammeter (0—1 or 0— 1.5A) connec- 
ted in series with the plate supply (the 
ground lead, if possible, for safety) will 
suffice for metering of the amplifier, A 
cooling fan is necessary if the amplifier is to 
be used at its maximum input rating. This 
can be simply connected across the primary 
of the power transformer so it is activated at 
the same time as the power supply is turned 
on. A 1 1 5 V fan which is popular is a Barber 
Coleman D YAF 761-110 with their 
AYFA-403 fan blades. The larger electronic 
mail order houses can supply this item. 
Other suitable surplus type fans can also be 
used, but there must be a good flow of air 
(about 100 cfm). The 6KD6 tubes run hot 
and I have seen several removed from TV 
sets where under normal operating condi- 
tions the glass envelopes have started to 
distort due to heat problems, 

The external connections for the amplifi- 
er sub -block consists of the usual rf input 
and output connectors, a relay connection 
for switching the linear to transmit via the 
exciter, and an ale connector for use with 
the exciter. The latter is an optional feature 
which can be used if the ale voltages needed 
by the exciter from the driven linear are 
known. 

The actual circuitry of the amplifier 
sub-block is extremely straightforward. The 
6KD6 tubes operate class AB in a grounded 
grid configuration. The tubes are not indi- 
vidually current balanced and this is not 
necessary as long as the tubes used are of the 
same manufacture. The input circuit to the 
cathodes of the tubes contains a low-pass 

filter (LI and the 100 pF capacitor). This 
filter helps to prevent further amplification 
of harmonics from the exciter used and 
improves the overall distortion rating of the 
linear. L2 is an rf choke which will pass the 
cathode current of the tubes while still 
keeping the cathodes above rf ground. The 
choke is quite easy to construct and consists 
simply of close wound turns of #24 wire on 
a 1.25 cm by 7 cm long ceramic or high 
temperature plastic form. L3 is the plate rf 
choke. One has the choice of using one of 
two simple approaches to construct a 
suitable rf plate choke. The choke I used is 
wound on a 9.5 x 2 cm ceramic form with 



#24 wire. It consists of five sections, each 
section separated by about 1 cm. The top 
section consists of 1 1 turns and the follow- 
ing sections are 16, 27 s 33 and 43 turns. A 
somewhat simpler rf choke can be made if 
desired, but then two chokes have to be used 
in series. The first choke is wound full with 
#24 wire except for 0.5 cm at the top and 
bottom. The second choke is an Ohmite 
Z-50. The .001 juF plate bypass capacitor is 
used after the Z-50 choke, not between the 
two chokes. 



Construction 

The amplifier sub-block is fully contained 

on a standard 5 x 7 x 2 in. aluminum chassis. 
The tube sockets are arranged in a semi- 
circular fashion with the rf plate choke in 
the center. The circle is arranged so the 
center of the end tube sockets are about 2.5 
cm away from the side of the chassis on 
either side, This will permit the tubes to be 
separated enough to allow good air passage 
while not allowing the rf leads to become 
too long. The rf plate choke is about 2.5 cm 
away from the edge of the chassis also. The 
tube sockets are oriented so that the number 
two pin (cathode) on the socket always faces 
the center of the semi-circle. At the rear of 
the chassis, the connectors used are a 
SO-239 for the rf input, phono jacks for the 
relay control and ale output (if used), and 
another SO-239 for the rf output. The ale 
adjustment potentiometer is also located on 
the rear panel of the chassis. The use of 




Rear view of amplifier shows arrangement of 
connectors. Single hole mounting SO-239's are 
used to facilitate bolting of amplifier sub-chassis 
into an overall enclosure. 



34 



73 MAGAZINE 



single hole mounting SO-239 connectors and 
phono connectors greatly simplifies the 
mechanical work involved. 

At the underside of the chassis the 
antenna transfer relay is mounted on one 
side wall above a tube socket and close to 
the front paneL There is no need to mount 
the relay in any exact position but it should 
be mounted nearly as pictured so the length 
of the wire between the rf output connector 
to the pi-network is as short as possible. This 
is to minimize coupling between the output 
line and the rest of the amplifier circuitry. A 
short piece of coax is used to go from the 
relay to the input connector. The zener 
diode for bias regulation may be mounted in 
any convenient location near the relay. The 
cathode of the diode is directly bolted to the 
chassis, as the chassis functions as a heat sink 
for the diode. 

The wiring of the cathode circuitry of the 
tubes deserves mention. This wiring should 
be kept as short as possible and an insulated 
terminal post is mounted for this purpose in 
the center of the ring of tube sockets. The 
post can be held in place by the same screw 
which supports the rf plate chocke on the 
top of the chassis. The cathode choke, L2, is 
mounted on the side wall of the chassis 
opposite the relay. The low pass filter coil, 
LI, is wired between the relay contact and 
the cathode terminal post in the center. Also 
the 100 pF capacitor associated with the 
filter is wired in beneath LI and utilizes the 
bottom of the center terminal post for 
ground, You can also use the ground post of 
the small terminal strip located in the middle 
of the inside front panel. This latter terminal 
strip supports the few components for the 
relative rf output level circuitry. The 100K 
resistor in this circuit can be seen going 
between the relay and the terminal strip. 
Each cathode pin of the tube sockets is 
connected with an equal length lead to the 
center terminal post. 0.5 cm wide copper 
material is preferred, but large size wire such 
as -1 2 or larger can also be used, 
simplify the wiring of the chassis is to wire 
the tube sockets as fully as possible before 
mounting them, then complete the wiring of 
the sockets on the chassis, mount the rest of 
the components on the chassis and then 
complete the final wiring. The whole process 



may sound a bit involved, but actually once 
the chassis has been drilled and the compo- 
nents assembled the whole wiring can be 

completed in an afternoon. 

All the pins on the tube sockets are wired 
to ground via the ground lugs on the sockets 
before mounting the sockets on the chassis 
except pins 2 (cathodes), 12 (filaments), 5 
and 9 (grids) and 7 (internal tube connec- 
tions). The two ,01 bypass capacitors associ- 
ated with each socket are wired in at the 
same time. Once mounted on the chassis, the 
filament pins (12) and grid (9) are wired 
together from socket to socket. The wiring 
to the power supply leaves the chassis via a 
grommet on the side wall opposite the relay. 

The mechanical working of the chassis 
can be done completely with hand tools if 
desired. The only large holes which require 
work are the ones for the tube sockets and 
the SO-239 connectors. These can be made 
with a punch or with a nibbling tool and 
round fiie. There is little sense in investing in 
a punch if one is not likely to use it again, 
but a nibbling tool can be used for a variety 
of chassis work, 

Pi-Network Circuits 

A number of pi-network circuits have 
been tried which will work properly with the 
amplifier. If the linear is to be used on only 
one or two bands, the pi-network circuitry 
becomes quite simple and one need only 
experiment with the component values that 
produce the highest power output. Extract 
the single band component values from the 




Bottom view of amplifier sub-chassis showing 
wiring of cathode leads to a central terminal point 
Note also placement of 3pdt relay on side of 
chassis. 



OCTOBER 1973 



35 



it wasn't easy. . .but 
Kenwood improved 



the 




599 & T-599 



THOUSANDS HAVE PROVEN 
THEMSELVES THROUGH DAILY USE. 
EVERYTHING THAT MADE THEM THE 
BEST REMAINS, BUT NOW KENWOOD 
DID THE IMPOSSIBLE BY MAKING 
THE "TWINS" EVEN BETTER. THE 
R-599A IS THE MOST COMPLETE 
RECEIVER EVER OFFERED... MANY 
FEATURES WHICH ARE "OPTIONAL 
AT EXTRA COST" IN OTHER 
RECEIVERS ARE STANDARD 



the R-599A 



Solid state . . , low power consumption, superbly 
reliable, small and lightweight • Full amateur band 
coverage . . 10 through 160 • CW, LSB, USB, AM, 
AM.N, FM reception » Selectable AGC . . . slow or 
fast • Built-in calibrator • Monitor T-599A 
frequency to calibrate transmitter • Squelch 
circuit • 1 KHz frequency readout. . , smooth VFO 
action • Versatile cross channel operation with T- 
599 A • Automatic or manual selectivity selection • 
Built-in SSB/8 pole, CW/8 pole and AM filters • RIT 
circuit with RtT tuning separate from RIT switch • 
Five built-in fixed frequency channel positions * 
Provisions for installation of 2 and 6 meter 
converters* Stable, accurate VFO • Built-in power 
supply for 115/230 VAC operation or 12 VDC 
operation • Built-in WWV reception • Built-in S- 
meter • Excellent sensitivity —.5 uv • Easily 
adaptable to use with Kenwood TS-900 • Modern, 
beautiful design 
New Features: 

New easy read dial, same 1 KHz readout . . . same 
smooth VFO action • Excellent built-in noise 
blanker • Improved 2 and 6 meter operation with 
optional accessory converters, easier installation • 
Continuous RF gain control replaces stepped 
attenuator • Built-in 11 meter coverage • AGC 




The R-599A by Kenwood 

turns off if desired • VFO indicator light for cross 

channel operation • 

The R-599A . . . $439.00 ♦ Converters . . - $31.00 • 

S~ 599 Speaker .,.$18.00 



the T-599A 



Mostly solid state . , . only 3 tubes • Built-in power 
supply • Full metering: ALC, lp, RF output* high 
voltage • CW, LSB, USB T AM operation * 1 KHz 
frequency readout, smooth easy VFO action • 
Built-in VOX, with delay, sensitivity and anti-VOX 
adjustments • Built-in semi-automatic CW with 
sidetone * Built-in calibrator function when used 
with the R-599A • Full amateur band coverage > . . 
10 through 80 • Versatile cross channel operation 
with the R-599A • Stable, accurate VFO • Modern, 
beautiful design • ALC feedback • Maximum TVI 
protection • 200 watts PEP input nominal • Tube 
saving TUNE position • Built-in cooling fan • 
Selectable low or high microphone impedance 
New Features: 

Front panel MIC Gain control • Front panel CAR 
LEVEL control • Improved, easy read dial, same 
smooth VFO action • VFO indicator light for cross 
channel operation • New high reliability final 
amplifier layout • Improved keying characteristics 
• New chain drive * 
The T-599 A.., $459.00 

Prices subject to change without notice. 



Why buy from Henry Radio? 

Over 40 years experience, No finance charges if paid 
with-in 90 days, tow interest contracts - 8%/yr add 
on (14% annual rate) - as long as 24 months. 70% 
down or trade-in down payments. Good used 
equipment. Most makes and models. Used 
equipment carries a 15 day triai 90 day warranty and 
may he traded back within 90 days for full credit 
towards the purchase of NEW equipment. Write for 
bulletin. Export inquiries invited. 



i 





11240 W. Olympic Blvd., Los Angeles, Calif. 90064 

213/477-6701 
931 N. Euclid, Anaheim, Calif. 92801 714/772-9200 
Butler, Missouri 64730 816/679-3127 



Available at Kenwood Dealers throughout the US 



multiband circuits shown in Fig. 3. Under 
properly loaded conditions and with 
800-900V on the plates, the CW plate 
current will run 200—220 mA per tube used. 
For the full five tube circuit, the plate 
current for CW can be loaded up to between 
$.. and 1,1 A. The key-down periods must be 
kept to 1 seconds or less. 

If an 80 to 10 meter multiband pi- 
network output circuit is desired, Fig. 3 
presents two good possibilities. The first 
circuit has an advantage in that it requires 
only a conventional 2 pole, 5 position switch 
for all of the capacitor and coil switching 
functions. The second circuit avoids the use 
of auxiliary fixed capacitors for the lower 
frequency bands but the plate tuning capaci- 
tor shaft requires an insulated shaft coupling 
and mounting above ground. In any case, the 
final coil tap positions should be experi- 
mentally peaked up for maximum power 
output on each band. The plate tuning 
capacitor in either circuit should have 
1000— 1500V spacing while the output load- 
ing capacitor need only be a broadcast band 
type. The fixed capacitors should be mica or 
ceramic types rated from 1 to 3 kV. Ceramic 
transmitting type capacitors such as the 
Centralab 850S are preferred if one can find 
them surplus at a reasonable price, 



? 



250/ tKV 

SPACING 




C0IL:5CM DIA.5CM LONG 
BAND TAPS 



40 -7T 
20- 3T 
15 - 2T 
10 - IT 



ANT, 



Jf 1000 TO 
# 1500 MAX, 



Huh ROLLER INDUCTOR 




n~^ 



~x 



-U00 \J 1000 MMF/ 
SECTION 



ANT 



PLATES 



I 



£ 



I500MMF 



Fig* 3, Two good pi-network circuits which can be 
used with a 5 tube 6KD6 amplifier for all band 
operation. 




Vfan 



J 



AMPLIFIER 
SUB-CHASIS 



RECTIFIER/ 
FILTER 




Fig m 4 M There are many ways the amplifier sub- 
chassis can fit into an overall enclosure to fit 
almost any taste m Build the sub-chassis first and 
then integrate it into an overall enclosure. 

Final Enclosure Assembly 

Exactly how one wishes to finish up an 
amplifier in an enclosure depends to a good 
degree on how fancy an appearance is 
wanted, so this part of the project is pretty 
well left up to the desires of the individual 
builder. Certainly, if the power supply is 
ready, the amplifier chassis finished and the 
parts for the output circuit secured, the 
grouping of these items in an overall enclo- 
sure is not a big problem. 

Although not one of the fanciest ap- 
proaches, but certainly a simple and ade- 
quate one which I have used for a number of 
amplifiers, is the use of standard large size 
metal utility cabinets (Bud CU or AU series, 
Par-Metal MC series) as the overall linear 
enclosure. These enclosures are inexpensive 
($5 to $6) and come in black wrinkle steel 
finish or bare aluminum. The black steel 
cabinets are attractive in that they need no 
further painting. These enclosures are typi- 
cally square looking with removable top and 
bottom covers. The mounting of the ampli- 
fier sub-chassis in such an enclosure is 
particularly simple since the connectors on 
the back of the amplifier sub-chassis can be 
used to secure the sub-chassis to the en- 
closure. Figure 4 shows how the total linear 
might be assembled in such an enclosure. 
For ventilation purposes, a series of holes 
should be drilled in the two side walls of the 
enclosure which are in the path of the air 
flow produced by the cooling fan used. 

> . .W2EEY 



OCTOBER 1973 



37 



LOOK INTO 
OUR CRYSTAL 



AND SEE BEYOND 

2 METERS 




The new 220 MHz Clegg 
FM-21 transceiver has a unique 
triple-duty crystal feature and offers 
you a chance to get away from to- 
day's 2 meter crowd. The FM-21 
uses just 1 crystal in any channel. 
One crystal gives you a separate 
transmit and receive frequency plus 
automatic 1.6 MHz programming in** 
the repeat mode. Our Crystal Saver 
Frequency Control is just one of the 
big pluses you get with the FM-21. 
another ail-American made quality 
rig from Clegg. For the whole story, 
see your Clegg Dealer or call or write 
us now for detailed data sheet an 
escape from the 2 meter crowd. 

Amateur Net $299.95 





Gm. 



CHECK THESE SPECIFICATIONS 

GENERAL 
POWER REQUIREMENTS: 12 to 14.8 

Standby Current: 120 Ma. 

Receive Current: 450 Ma. 

Transmit Current: 1 .5 Amps. Max. 
FREQUENCY RANGE: 220 to 225 MHz 

Power output down less than 2 db at 

220 MHz 
DIMENSIONS: 7" wide x 2%" high x 

9" deep. 
cpfC RECEIVER 

SENSITIVITY: 
, 25^ (Max.) for 12 db SINAD 

SELECTIVITY: Adjacent channel 

(40 KHz) down 50 db 
AUDIO POWER: 1.5 watts at 10% THD 

to internal or external speaker 
SQUELCH: Noise actuated, adjustable 

threshold. .2 to 2/iV min. range 

MODULATION ACCEPTANCE: ±7 KHz 

POWER OUTPUT: 8-10 watts (min.). 

MODULATION: PRE-EMPHA5IZED FM 

with deviation adjustable from to 7 

KHz. Adjustable speech clipping up 

to 10 db. 



DIVISION 



3050 Hempland Road Lancaster, Pa. 17601 
Tel: (717) 299-3671 Telex: 84-8438 



John A. Meissner K5CXN 

2223 48th Street 

Los Alamos NM 87544 





T ANOTHER 
WATTMETER 



Many VHF operators would like a 
cheap, accurate instrument to mea- 
sure rf power. The same desire is frequent- 
ly expressed by operators of the HF bands. 
Here is a very simple wattmeter which 
when used with a SOfi transmission line or 
load has all of the following desirable 
characteristics: 

1. Easily calibrated to good accuracy 
(±5%) with your multimeter and a variable 
dc source; 

2. Perfectly flat from dc to 450 MHz; 

3. Insertion VSWR less than LOS 

4. Power readings in the 2 to 50 watt 
range (higher power can be measured with 
slight design changes); 

5. Cost of approximately $20,00, 
assuming the use of a surplus micro- 
ammeter. 

The operating principle of this watt- 
meter is stark simplicity. A pilot lamp 
across the rf line senses a small portion of 
power in the line and glows brighter with 
increasing power. An appropriately located 
photovoltaic cell connected to a micro- 
ammeter measures the light output which is 
proportional to the power flowing in the 
line. Of course a good deal of nonlinearity 
is involved in the various elements — both 
the lamp's resistance and its spectrum 
output change with heating; output of the 
photovoltaic cell varies considerably with 
both the amount and frequency of the 
light shining upon it. Some of these factors 
tend to cancel out however, because the 
photovoltaic cell produces some current 
with only infra-red lamp output at low 
power levels before the lamp even produces 
a visible glow, and the cell tends to 
saturate, increasing its output quite slowly 
at more intense illumination levels. 



if the resistance of the lamp filament is 
very large when compared to the line 
impedance. In general, a factor of 15 or 
more times the line impedance is suffi- 
ciently large to produce negligible effects. 
In the case of the suggested 10V, ,014 
Ampere pilot lamp, the mismatch produced 
in the line gives a VSWR of 1.05:1 at the 
power level of 1 watt. This mismatch 
decreases rapidly with increasing power. It 
falls to well below 1,01:1 at 50 watts. 
Another point of interest with regard to 
this particular choice of lamp is that it is a 
long-life type with a life expectancy of 
10,000 hours. This implies two advantages: 
(a) The lamp will operate at well over its 
rated voltage without burnout (50.0V at 50 
watts), and (b) the interior of the lamp 
envelope will resist darkening which would 
negate the wattmeter calibration- In addi- 
tion, the filament structure of this type of 
Probably the biggest single requirement 
of any wattmeter is that it must be capable 
of being inserted into a transmission line 
without disturbing the operating conditions 
in the line (low insertion VSWR). It might 
be argued that hanging a lightbulb across a 
transmission line will seriously affect the 
line impedance. Ordinarily, this is true, but 
the undesirable changes can be minimized 
and indeed approach an insignificant level 



UG-J07A/U 

UHF COAXIAL "TEE" 



RF IN 



RF OUT 



/ 



/ l\ 



DIALCO LAMP WO. 39J0 
g7t *BASE REMOVED) 



z^^ 



RS NO. 
£76-115 

PHOTOVOLTAtC CELL 



20^i A 
DNNECTORS 



SDl j 



MIN1BOX - BUD NO. CU-3000-A 



COAX CABLE OR 
TWISTED PAIR Q lo 

50 



10- WATTS MAX-RI'95U.IW 
50- WATTS MAX- flZ- 20ft r 100ft. t/4 W 

IN PARALLEL 





50 f 3 

f RZ r 



Fig. 1, Schematic diagram. 



OCTOBER 1973 



39 



lamp is a single-strand straight tungsten 
wire. The coiled type of filament structure 
introduces undesirable inductance into the 
circuit which can distort wattmeter read- 
ings in the UHF range. 

The wattmeter shown is constructed in 
two boxes for the sake of convenience. The 
sensor can be located in the transmission 
line at any point and the meter can be 
placed beside the transmitter. For test 
work, the whole unit could easily be put 
into a single box- Coaxial fittings and cable 
were used for interconnection, but since dc 
only flows in this circuit, any type of 
wiring would be satisfactory. 

The photovoltaic cell used in this watt- 
meter is a unit obtained from the local 
Allied/Radio Shack store. (Catalog No. 
276-1 15.) Output of the cell is rated ,5V at 
.6 mA in sunlight. 

Since the cell generates considerably 
more than 20 mA under moderate illumina- 
tion, a switching arrangement is incorpora- 
ted into the wattmeter to shunt it into 
progressively higher current ranges with 
increasing power. Alternatively, a 50 or 
100 milliammeter could be used with less 

switching at a sacrifice of sensitivity in the 
1-3 watt range. 

Calibration of the wattmeter is a simple 
process. By solution of the formula P = 
V /R for voltage, the following tabulation 
is made for a 5 Oil line impedance: 



VOLTAGE 


POWER 


(rms or 


dc) 


(Watts into 50J2) 


7.07 




1 


10.00 




2 


12.24 




3 


14.14 




4 


15.71 




5 


17.32 




6 


18.71 




7 


20.00 




8 


21.21 




9 


22.36 




10 


31.62 




20 


38.71 




30 


44.71 




40 


S0.00 




50 



Using the tabulation, fasten a metered 
variable dc supply into the wattmeter ac- 
cording to the following diagram. Now 



simply note the reading on your wattmeter 
for each of the selected voltages in the 
table and tabulate this reading with the 
corresponding power in watts in a table of 
your own. It may even be possible to 
remove the front of the meter case and 

mark new calibrations directly on the dial. 
This was not possible with some hermeti- 
cally sealed meters. It is best to disconnect 
the wattmeter from the antenna feedline 
for this calibration- If the meter is left with 
a transmission line attached and the an- 
tenna happens to be fed through a balun 
device with near zero resistance, the power 
supply, and perhaps the balun, will suffer. 



UHF TEE 



AC INPUT 




VARIABLE 

VOLTAGE 
DC SOURCE 



OP£N 
END 



TO 
METER 



VTVM OR 
MULTIMETER 



Fig. 2, Calibration diagram. 



It must be pointed out again that this 
power meter is intended for use either 
with 50J1 coaxial line systems with low 
VSWR or with 5012 dummy loads. A 
coaxial line that is not "flat*' (unity 
VSWR) or a dummy antenna that does not 
look like" 50fi, which is the case with 
most HF loads used at VHF or UHF, may 
cause distorted power readings. If you have 
doubt about your transmitter's power out- 
put when using this meter, you should 
check it while using a known 50O load 
rated at the transmitter's output frequency. 

1 mentioned before that this power 
meter was easily adaptable to higher power 
readings. To upgrade the meter, the only 
change required is to insert the correct 
higher voltage pilot lamp having low cur- 
rent, long-life specifications. Suggestions for 
some of these are the following Dialco 
Lamps: 

Part No. Max Power Level (Watts) 

24CS 1 00 

48CS 200 

60PSB 340 

120PSB 800 

. . .K5CXN 



40 



73 MAGAZINE 




SCAN- 
VISION 



SCANVISION 

SLOW -SCAN 



■ iflT 



Fully meets all 
accepted SSTV 
standards. 
Compatible. 



Exclusive! 
Built-in, 

casette-type 
recorder* 
Ready 
Instantly 



Now — unexcelled picture performance with exclusive- 
feature equipment of highest quality in which the 
most advanced SSTV techniques are expertly ap- 
plied — Sit Scanvision* Here, carefully considered 
design has simplified operation to the point where 
the non-engineer radio amateur can have his SBE 
Scanvision monitor connected and start enjoying 
slow scan in just a matter of minutes. 

Most of the many hundreds of SS TV'ers now active 
on the air agree that the full excitement and enjoy- 
ment of SSTV can best be realized only when a tape 
recorder is part of the system. Incoming pics are 
taped for future viewing on SS monitor — pre-taped 
pictures, scenes, l-D — can be transmitted, So — ex- 
clusive! — every SBE Scanvision monitor has a cas- 
sette-type tape recorder built-in — wired — ready to go 
and selectable with panel switch. Here is the ultimate 
in convenience. 



Scanvision is conservative — reliable, with pic- 
ture-proved circuitry and is all solid-state except for 
the scope tube in the monitor and the videocon pic- 
ture pickup tube, heart of the SB-1CTV camera, Both 
tubes are standard types with predictable character- 
istics^ — not surplus- 
High quality is everywhere evident — throughout, the 
to-be-expected SBE approach — fastidious — profes- 
sional- The SBE Scanvision, S8-1 MTV Monitor, com- 
plete with casette recorder and SB-1CTV Camera with 
f/1,9, 25mm lens, connect with patch cable to com- 
prise ft system- Units are also separately available* 

SEE SCANVISION AT YOUR SBE DEALER 









Audio in,., and out 
NO MODS!! 



if=i. 



1 



Available- 
camera with 
high quality 
videocon for 
"live" or 
"still" pics. 



Camera is 

supplied with 

quality f/1. 9, 

25 mm lens. No 
extra charge. 



Monitor con- 
nects to spkr 
or phones for 
receive— to 
mic input for 
transmit. 



"Live" SSTV 
pic photo- 
graphed from 
monitor, Un- 
retouched. 



1SBEI 

LINEAR 
SYSTEMS, INC. 

220 Airport Blvd. 

Watsonvilie. 
CA 9SQ76, 




you like 



METER 



YOU'LL LOVE OUR 




15 OR 1 WATT POWER OUT/ SWITCH SELECTABLE/ 
FULL 12 CHANNEL TRANSMIT AND RECEIVE CAPABILITY 

Youll like the crystal clear transmit and receive performance 
of this compact, 2 meter unit and so will those listening. The 
12 transmit channels are provided with individual trimmer capaci- 
tors for the optimum in point-to-point and repeater applications. 
A HI/LO power switch provides 1 watt output or full rated output. 
The receiver has an audio output of 3 watts at excellent sen- 
sitivity, Solid state, American made quality at a low price. 





$229 



00 



AMATEUR NET 



k * 



frftt nam* I in iplid ftrtf Wl l 



includes plug-In ceramic mike, 
mounting bracket and transmit and 
receive crystals for 146.94 MHz. 



THE FM LEADER IN 2 METER AND 6 METER... AND NOW 220 MHz 




J. K. Bach WB2PAP 
Ivy Hill Road 
Walden NY 1 2586 



^DEMAIN 



Nobody in his right mind would fix a 
meter by choice, any more than he 
would operate on his wrist watch. But fate, 
which seems to be a generalization of 
Murphy's law, determines that sooner or 
later you will be faced with the necessity. 
One day you are minding your own business 
and your boss sidles up to you like an 
affectionate bison, mumbling something 
about how easy it would be for you to fix 
this (heh heh!) meter in your spare time. Or 
it's your own meter that went ape on a 
weekend. Whatever the motivation, you de- 
cide to take a hack at it. 

I had never fixed clocks or watches, but I 
had reversed a tuning meter or two to read 
up-scale, so meters held no terrors for me. 
The first time I was handed one to fix at 
work, I started out with a show of jolly 
self-confidence and proceeded to lose my 
patient — irretrievably — within minutes- 
The second worked if you tapped it continu- 
ously and held your mouth right. The third 
and fourth I don't remember, but the fifth 
worked as good as new. By this time I had 
made most of the more stupid mistakes, 
learning a bit from each. A meter repairman 
would laugh himself sick at my methods. 
Were I in his position, with his facilities and 
skills, I would laugh too. Vd laugh even 



harder watching him work on a meter with 
my facilities. He has to work fast to make 
money and has all the parts he needs. He 
replaces whole assemblies, as an automobile 
mechanic does. I have to straighten the kinks 
out of hairsprings, but I have lots of time. 
My boss gives me the job because when he 
sends any meter to any shop he knows how 
long it takes to get it back. This is true of all 
shops all over the land. Even buying a new 
one takes a lot of time, which is why so 
many of us are volunteered to fix them* 

The tools are very simple. A good light, 
such as a desk lamp, is very useful but not 
essential if you have young eyes, I haven't. 
The next thing is to provide a spread 
newspaper to work on. Meter magnets will 
attract steel filings and steel wool fuzz from 
incredible distances. These have to be 
swabbed out of the air-gap with Scotch tape- 
One session of this will teach you to spread a 
clean newspaper. 

The second lesson is, no magnetic tools. 
You naturally try to use your familiar 
long-nose and screwdriver, but at best you 
can't control them closely enough near the 
magnets and they are hazardous besides. 
What you need is a non-magnetic toothpick. 
It can be round, like the one in the 
photograph, or the old square kind. You can 




Fig. la. Top view of a healthy meter spring. 



i 



^P 



Fig. lb. Side view with indicating needle added. 

cement two together to make a tiny fork for 
straightening needles and unkinking hair- 
springs. 

By all means get a magnifying glass if you 
can. Older guys tend to keep them in their 
toolbox. One of the handiest kinds is the 
jewelers* loupe with the steel spring head- 
band on it. The monocle type will cramp all 
the muscles from your big toe up, with the 
effort of keeping the silly thing in your eye. 
Use your own judgment. 

Duco or other plastic cement is handy, 
hut do not use it directly. If you have to 
cement a needle, transfer an invisible dab of 
cement with the end of a toothpick. Get just 
one drop of cement in a hairspring and no 
amount of any solvent will ever get it out. 
The only cure is to take the meter in your 
right hand, take a good wind up and let fly 
eastward. This will save you an ulcer in the 
long run- 
All this talk and nothing about the actual 
work yet? Patience! Watch a good machinist 
at work — two hours and a half on setup, 
and two minutes for machining, that's his 
rule. The beginner reverses these times and 
strikes out with ruined work. Meter fixing is 
like this - utter despair can be followed by 



delirious delight within a few seconds. 
Nearly every hairspring trouble is fixed very 
suddenly or not at all. And all the other 
troubles taken together are few. 

One more warning; the PAP syndrome 
(WB2PAP). This is not to be confused with 
the PAP test which is entirely unrelated. The 
effect is a spasmodic jerk of the hand which, 
by Murphy's law, invariably stretches the 
hairspring to its full length and ruins it. This 
nervous jerk is brought on by fatigue, and I 
believe it is due to the loss of feedback to 
the brain, which tries to locate the hand 
position and reset it, with disastrous results. 
I don't fully understand the mechanism — 
who does? — but I know a good way to 
prevent it. Never work free hand. Take a 
look at the photograph which illustrates this. 
See that third (fiddle count) or fourth 
(piano count) finger touching the meter 
magnet? With it, or any other finger or part 
of the hand touching, the brain knows right 
where the hand is, and keeps it there. Also 
the movements are measured in millimeters, 
not inches, and finger contact helps with 
this. It also helps impose gram forces instead 
of ounce forces. There, I've saved you one 
meter already. 

Another warning - leave the jewels and 
pivots alone. With a brand new meter, fresh 
out of the box, you can move the needle 
along its length a full thirty-second inch, a 
clearly visible amount. You can even feel the 
motion of the pivots in the jewels. Every- 
body has a thing about pivot adjustments, 
and so did I, once. The natural thing is to 
take all the slack out — just. But meter 
pivots should be left sloppy for the least 
drag. 

If you must take meters apart beyond the 
minimum possible stage, you will need some- 
thing to put the little screws and nuts and 
insulators in. I like a baby-food jar. A heavy 
ash tray is good too; or both. But keep the 
parts in the jar until you have to put the 
meter together again, else you may hit the 
ash tray with your elbow and shower itsy- 
bitsies all over the place. And tweezers — 
sound good? Like the idea? Ever "shoot" a 
little nut or screw clear across the room and 
into the nap of the rug? Maybe you have the 
requisite skill to use tweezers, but 1 want no 
part of them. 



44 



73 MAGAZINE 



At last — the broken meter. Take the 
front case off. Is the winding open? Blow 
the needle to full scale a few times and see 
how quickly it restores to zero. Now short 
the terminals and repeat. If the needle 
restores as fast as before, either the air-gap is 
very wide or you have a wiring trouble. It 
figures to be the coil, but several times I 
have found it in the shunt or multiplier 
resistances, or other wiring. 

Now if the needle is stuck, make sure it 
really is the needle. It can actually stick to 
one of the stops (rare), scrape on the scale, 
hook over a scale-screw, or be biased off low 
mechanically. In any case the needle must be 
okay before any other source of drag can be 
located. The air-gap may have filings in it, or 
the hairspring tangled. 

If the air-gap is fouled up, take a short 
length of Scotch tape and swab it clean. It 
isn't fun, but it can be done. 

If the hairspring is tangled or distorted in 
any way, the best thing is to just look at it 
from all angles, in all kinds of light, under 
the glass (low powered one will do). Try to 
figure out just how in thunder any normal 



very difficult to see unless you have experi- 
ence. Someone before you has had the meter 
open and touched the hairspring not quite 
gently enough. He has put a permanent set 
at the outer attachment, bending it toward 
the shaft right where it is soldered, along the 
horizontal plane of the spring. You can work 
at this for hours, making it worse and worse. 
But once you know exactly what the trouble 
is, you take the non-magnetic toothpick and 
bend it in the exact opposite direction, 
removing the "set" and restoring the original 
set. But don't apply the restoring set all at 
once, and directly against the arrow in the 
figure. Rather, engage the sharpened tip of 
the toothpick between the 3rd and 4th loop 
of the hairspring and run it back and forth a 
few millimeters - maybe an eighth of an 
inch — along the spring, but angled very 
slightly outward. Magic! That spring, under 
the glass, is one of the most beautiful things 
you will ever see! 

Or take Fig. 2b. By great good fortune, I 
managed to get something like this in the 
photograph, I was working left-handed at 
arm's length with a commercial photo- 
grapher, tripod, Hasselblad, and speed-flash 



S* 





Fig, 2a. Spring is bent at outer attachment. 

human being could get the hairspring in such 
shape — but don't touch it yet, just look at 
it. This will save you a lot of time. 

Figure la sketches a view of two moving 
paits-h air spring and shaft with side-lug. Also 
shown is the zero adjusting fork, which also 
revolves around the same axis as the shaft 
and pivots. Figure lb is the same thing from 
the side, with the indicating needle added. 
No fixed supports or anything else are 
shown. All this for comparison. 

Now look at Fig. 2a - what causes the 
bunching at the bottom of the coils? This is 



Fig. 2b. The outside loop is hooked over the 
spiral 



all between me and what I was doing. The 
only way I could tell that I was contacting 
the hairspring was that the meter needle 
quivered a little from time to time. See that 
little loop up past the outer turn of the 
hairspring? That's how it looks, except that 
it stays there by itself and hangs the meter 
movement up. Same remedy here: move the 
sharp tip of the toothpick a little further 
back this time until the spring jumps clear. 
Imagine you are petting a microbe; this will 
help you use a minimum of force. This, by 
the way, is the only trouble that ever clears 



OCTOBER 1973 



45 








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itself, and not very often, either. I think that 
slamming the needle is what does it. The 
sharp pulse sets up a standing wave that 
whips a loop of hairspring outside the spiral, 
where it catches. 




Fig. 3. This anomaly was probably caused by the 
downward motion of the adjusting fork. 

• 

Figure 3 is interesting, too. Obviously, 
someone has hit the scale end of the 
adjusting fork, pushing it downward. So take 
your tool and twist it back up. These 
"repairs" (adjustments) take five minutes of 
looking and five seconds of adjusting, Or five 
hours if you mess it up or "fix" the wrong 
thing, A good visual imagination is the 
secret. Of course, the examples illustrated 
are frequently encountered and basic. But if 
you get any two of them together at the 
same time, or even a third mixed in, then the 
others will be more obvious and can be 
cleared in their turn, I never said it was easy, 
but you can do it, nevertheless, if you look 
before you poke. Most people don't. 

Consider: The hairspring is foil thin, it is 
made of phosphor-bronze, one of the tough- 
est metals, perfect for the purpose. It wants 
to go back like it was. Both ends are 
soldered fast, which limits the degree of 
possible entanglement, a sort of antithesis of 
Murphy's law. The worst thing is kinking 
and this is also due to big, vulgar, ignorant 
thumbs getting into the hairspring- Even 
these can be straightened one at a time, and 
suddenly the hopeless case is perfectly okay. 
Some traces may remain, but if the spring is 
symmetrical, and the eye can't be fooled in 
this, then by all means let it alone I Once you 
have sufficient clearance, twice as much isn't 
better, and costs in another dimension. 

Generally it is not necessary to remove 
the scale. Mount the meter level and se- 
cure — in a box, or something. If the meter 
slips and you make a grab for it and stick 
your highly-skilled thumb through the hair- 



spring, it will have exactly the same affect as 
if the office oaf stuck his in. You won't feel 
any better, anyhow. 

Once I got a meter in a tube tester that 
was supposed to stick. Impossible! It was a 
taut-band type, with pole clearances you 
could throw a cockroach through, I returned 
it and got it back, with the needle stuck this 
time. Out of the case, it came unstuck and 
no possible place to stick could be seen. By 
considerable mistreatment I managed to 
hang the needle up on a scale-screw. Bending 
the needle up a bit fixed things, 

A funny one: a meter with no needle at 
all, I was offered affidavits that the case had 
never been opened, but still - no needle 
anywhere. What could I use for one? Broom- 
straw, inked? Broom? Push-broom!! I 
plucked a horsehair from it — perfect. How- 
ever, 1 ironed it straight on the soldering 
iron, and dampness finally re curled it. I 
should have picked the longest and straight- 
est and let it go at that. 

How about calibration? You have re- 
stored the spring to its original shape, and 
very probably the calibration is pretty goodL 
You can set the zero adjustment in the 
middle of the adjuster range by moving the 
hack hairspring lever (be very careful of this 
one, the lever is short and you risk a Fig. 
2a), Once you get the zero okay, how about 
full scale sensitivity? You could adjust the 
shunt or multiplier, or if you are lucky, 
there might be a magnetic shunt. This gadget 
is a thin leaf of magnetic material that can 
be slid across the poles to leak a little of the 
flux around the coil. For more sensitivity, 
slide it back over the magnet away from the 
pole. This forces more of the flux through 
the air-gap and coil, increasing sensitivity. 
Only the very best domestic meters have this 
feature. Hickok even had one around the 
outside of the meter case in the big Gm 
meter of one of their tube testers. 

It is usually pretty disillusioning to cali- 
brate or compare meters. It really shouldn't 
be, but even the best meters aren't as 
accurate as you think. If they were, they 
would be too fragile and expensive to use. 
We've been getting along with them very 
well for years, just as they are. 

And if you have to fix one — good luck! 

. . WB2PAP 



OCTOBER 1973 



47 




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Imagine being able to use a IW FM 
transceiver and work stations in West and 
East Germany , Austria, Czecko Slovakia, 
Yugoslavia, Italy, Switzerland and France! 
This range of coverage is available through 
the Zugspitze repeater located in the Alps in 
southern Germany, The Zugspitze repeater is 
probably one of the most unique repeaters 
yet to operate in the 2 meter band. Its story 
is an interesting one not only because of its 
location, technical details and the German 



amateurs involved but because it may well 
become the model for a number of DX 
repeaters located throughout Europe. So, 
although American amateurs won't be using 
this repeater, except perhaps when on vaca- 
tion in Europe, its story should be of value 
and interest. 

Before describing the history of the re- 
peater itself, and unless one Is familiar with 
southern Germany, it would be a good idea 
to take a look at a map of Europe and locate 




A panoramic view from the Zugspitze Mountain. 



OCTOBER 1973 



49 






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the city of Munich in southern Germany. 
Within a radius of 200 to 250 miles coverage 
around Munich are located portions of all of 
the countries mentioned above. These 
countries cannot be worked directly from 
Munich because of lack of height, interfering 
terrain features, etc. However, if one pro- 
ceeds southward from Munich, the country- 
side remains relatively flat to gently rolling 
hills until about 50 miles southward when 
one rather suddenly encounters the start of 
the Alps, A number of peaks rise to several 
thousand feet in height, One of the most 
famous of these peaks and one of the highest 
(9, 721 feet) is the so-called Zugspitze. It is 
not the highest peak in the Alps but it is the 
highest peak in the portion of the Alps 
which cover Germany and the peak is right 
on the border between Germany and 
Austria, A meteorological observatory as 
well as a hotel are located on the peak and 
the area is a favorite with skiers. The view of 
the Alps provided from the peak on a clear 
day is perhaps one of the most spectacular in 
Europe, It is reached by means of a rack and 
pinion railway (not too scenic because of all 



the tunnels it travels through) or by an aerial 

cablecar ride that is guaranteed to fascinate 

anyone. 

When the 2 meter FM repeater idea began 

to catch hold in Germany it was natural that 
the amateurs in Munich looked toward the 
Zugspitze because of its high location and its 
accessibility. Approaches were made to the 
Bavarian Weather Service which maintains 
the weather station on the mountain to be 
allowed to set up a repeater on top of the 
weather instrumentation tower, After some 
rather difficult sessions with the weather 
service people* the German amateurs in- 
volved in the project finally did obtain 
permission to set up the repeater. Some of 
the conditions involved were rather hard to 
take, however. For one thing, the repeater 
installation could not be located indoors but 
had to be contained in a metal enclosure 
outdoors. Only a power line to the repeater, 
which would be metered and separately 
charged for, would be provided. Also a 
liability insurance policy in the amount of 
some $250,000 had to be taken out to 
insure that should the installed equipment, 
antennas, etc., cause any damage to the 
weather installation or to a person (there is a 
tourist observation platform around the 
weather station) that the weather service 
would be protected. 

It required considerable determination on 
the part of the amateurs involved to forge 
ahead under these conditions, especially 
since at this point the financial support for 
the project would have to come solely from 
the amateurs themselves. It might be worth- 
while at this point to mention that although 
only a few amateurs did all the work on the 
project, all amateurs can use the repeater. 
Private or "closed" repeaters are simply not 
allowed on the 2 meter band in Germany. 
The makeup of the repeater channels in 
Germany has been described in other articles 
and so it won't be gone into in great detail 
here. But either because of the Teutonic 
characteristic for having everything done by 
a rule book or because German amateurs saw 
the mess that was developing about repeater 
frequencies in the U.S., when repeaters were 
first authorized in Germany specific chan- 
nels were set up for their usage. Only these 
channels could be used and every new 



50 



73 MAGAZINE 




A view of the weather station on the Zugspitze, The transmitting and receiving antennas are directly 
above and below the tubular structure on the right side of the tower. 



repeater that was set up had to use a channel 
that would be compatible with other nearby 
repeaters. Originally 3 channels for repeaters 
were allocated and this now has been ex- 
panded to 7 channels. The input channels 
for repeaters are in the range of 144.15 to 
144.30 MHz with 25 kHz spacing and the 
output range is 145.70 to 145.85 MHz, 
Repeaters can have a maximum power of 
15W and ±5 kHz deviation. To enter the 
repeater initially a tone burst of 1750 Hz is 
required (most will also whist le-on) and then 
the repeater is carrier keyed as long as no 
break of jnore than 3—5 seconds occur. The 
amateur licensed to operate the repeater also 
has to be able to remotely disable and enable 
it. However, a separate link is not required 
and this control function is done by a 
multiple tone signal on the input frequency 
of the repeater. 

There were many amateurs in Munich 
who contributed to the establishment of the 
Zugspitze repeater, but the leading members 
of the team were Sepp DJ9HJ, Bernd 
DL9ZD and Peter DJ3YB. This team was 



perhaps an ideal one for such a project 
because of their complementing interests 
and talents. DJ9HJ headed the organiza- 
tional aspects of getting the repeater estab- 
lished while DL9ZD specialized in digital 
and control circuits and DJ3YB was an 
experienced engineer on VHF/UHF cir- 
cuitry. 

After receiving the necessary license for 
the initial Zugspitze repeater in the spring of 
1970, the Munich team set about to 
assemble the necessary equipment to get the 
repeater into operation as quickly as pos- 
sible. The emphasis at this point was to get 
the repeater into operation during the good 
weather period. Fortunately a commercial 
VHF transceiver intended for mobile use 
could be secured, and with the necessary 
modification for a power supply, frequency 
changes, a keyer for repeater ident, etc., it 
formed a repeater "package." Two com- 
pletely sealed vertical dipole antennas of 
commercial design and a cavity filter made 
up the antenna part of the package. After 
initial testing, the entire package was trans- 



OCTOBER 1973 



51 



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The original Zugspitze repeater housing. The entire 
repeater is located outdoors. 

ported to Garmisch, Germany, in August 
1 970, where it was loaded on the cable car 
for transport to the Zugspitze- The station 
package except for the antenna had been 
assembled in a metal container intended to 
remain outdoors. Over a day was required 
for the initial setup of the repeater and all of 
the usual Murphy's laws applied, as it was 
found the metal container was too large for 
the space it was meant to occupy, etc. None 
of these problems would normally have 
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work at 9,000 feet elevation and rides up 
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SI 5 each because of the equipment that had 
to be transported. Finally the repeater was 
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operation — but for only eight days. Then 
the repeater seemed to malfunction as the 
receiver sensitivity was greatly reduced. The 
cause was traced to the cavity filter used for 
antenna isolation. It had been constructed 
from 1 mm thick copper but apparently this 



52 



73 MAGAZINE 




A view of the transmitting antenna in summertime. 
The antenna is a completely weather-sealed vertical 
half -wave radiator. 



thickness could not remain properly ad- 
justed due to the temperature extremes 
encountered on the mountain, A look in the 
statistical records showed that the tempera- 
ture on the Zugspitze, to which the entire 
outdoor installation would be exposed, 
varied from -37 degrees to +70 degrees. The 
average temperature is about 24 degrees, the 
same as that for Greenland. The problem 
with the cavity filter could not be solved, 
but an anonymous donor came up with a 
commercial 5 pole filter that did the job. 

After solving the filter problem, the 
repeater basically continued in operation 
with only minor difficulties. The transmitter 
used was a tube type and had only 5W 
output. Nonetheless, German amateurs were 
pleasantly surprised to find at times Italian, 
Czeck and other DX stations calling over the 
repeater. Also, the coverage achieved in 
Germany was considerable, with stations 
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The transmitting antenna after a winter storm. 
Temperatures easily drop to -37 

fere with almost every other repeater in 
Germany operating on the same channel. 
Since the Zugspitze at this time was set up 
to be a part of the overall German repeater 
network and not a special repeater, the 
interference problem with other repeaters 
had to be solved. The obvious solution was 
taken of reducing the transmitter power to a 
little over ViW. This power level still provi- 
ded more than adequate service using the 
repeater throughout most of southern 
Germany and the repeater functioned in this 
manner throughout 1971. 

However, the vision had certainly been 
created in the minds of the Munich amateurs 
as to what could really be done with the 
Zugspit2e repeater if it was brought up to 
full power level and allowed to operate on a 
clear channel. A reorganization of the 

German repeater network channels in late 
1971 made provision for the Zugspilze 
repeater to be set up on a separate clear 
channel (enter on 144,275, receive on 
145.725) and planning was started on com- 
pletely re-equipping the repeater. 

The team of DJ9HJ, DL9ZD, DJ3YB and 
other Munich amateurs again got together 



and decided that rather than try to refurbish 
the old repeater equipment to build a 
completely new installation using high per- 
formance equipment and specifically de- 
signed for the environment found on the 
Zugspilze. Although by now there appeared 
to be some hope of getting the radio clubs in 
the southern Germany area to help defray 
the cost of the equipment, the initial expen- 
ditures were totally those of the individual 
amateurs concerned with the project. The 
equipment designs that evolved for the new 
Zugspitze DX repeater would deserve several 
articles in themselves to describe it all 
completely. The equipment was totally 
home-brewed, but with a quality I have 
seldom seen matched in the finest com- 
mercial gear. 

Basically the total equipment package fits 
in a container about T x V/i x 2" high and 
consists of the antenna filter, receiver, trans- 
mitter and control and call-sign identifier. 
Each unit has been tested in an environ- 
mental chamber to simulate the extreme 
conditions encountered on the mountain. 
The receiver consists of a FET input rf 
amplifier stage working into a mixer using 
four HP2800 hot carrier diodes to translate 
the signal frequency down to 10.7 MHz. At 
10.7 MHz several crystal filters are used to 
achieve a 20 kHz bandwidth and then a 
phase-locked loop circuit is used as a FM 
demodulator. The noise figure of the basic 
receiver is slightly over 2 dB and the noise 
figure of the entire receiver side of the 
repeater including the effects of the antenna 
isolation filter is 3.5 dB, The squelch sensing 
circuitry operates on a dual frequency 
sampling basis to guard against accidental 
trip by stray interference. The transmitter 
side of the repeater, which is also fully 
transistorized, produces 15W output. In 
order to avoid the generation of many 
spurious signals which is usually the case 
when one starts with a low frequency crystal 
and multiplies it up to 144 MHz, a different 
frequency generation scheme was used. This 
was considered useful because the transmit- 
ter had to operate so closely to a very high 
performance and sensitive receiver. Figure 1 
shows the transmitter frequency control 
scheme. A Voltage Controlled Oscillator 



54 



73 MAGAZINE 









TO 

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TX 










-f 




& 






VCO 




DIVIDER 


*v 


PHASE 
DETECTOR 


MULTIPLIER 


REFERENCE 

xtal osa 




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FILTER 


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CONTROL 
VOLTAGE 







Fig. 1. Principle of operation of transmitter frequency control system. 



operating directly at 145,725 MHz is used. 
The output frequency is divided down and 
then compared in a phase detector with the 
frequency of a reference crystal oscillator 
which has been multiplied up in frequency. 
The resultant difference control voltage 
from the phase detector is used to control 
the frequency of the VCO. The VCO is 
directly FM modulated by an audio signal, 
the control voltage from the phase detector 
being made slow enough not to react on the 
modulation. The control, alarm and call 
identifier chores are taken care of by cir- 
cuitry consisting of some 24 ICs from Texas 
Instruments. The call repeater works on a 
shift register principle and is timed to send 
the call (DB0ZU) every 80 seconds. If the 
transmitter has not been keyed by a user, 
the transmitter is turned on just for the 
duration of the ident. Normally, a tone burst 
of 1750 Hz is necessary to key the repeater. 
It then remains carrier keyed for 1 5 seconds 
after which the tone burst has to be repeat- 
ed. If someone should open the repeater just 
as it is about to identify itself via F2 3 the 
ident is skipped until the next 80 second 
period. This is to prevent the call from a 
weak DX station being obscured by the 
repeater identifer signal. 

The subject of the antenna to be used 
with the new repeater was often debated. 
Since the new repeater was intended pri- 
marily as a DX repeater, the idea of hori- 
zontal polarization became popular since the 
repeater would be primarily used by home 
stations. However, this idea was eventually 
dropped and it was decided to leave the 
repeater with vertically polarized antennas 
so mobile stations could also easily use the 



repeater. Furthermore, since the antennas 
already installed performed without failure, 
it was decided to leave them in operation for 
the time being. The only fault with the 
present antenna installation is that as one 
can see from oiLe of the photos, the receiving 
antenna is partly shadowed by a portion of 
the weather tower. The ultimate plan is to 
use only one antenna for both transmitting 
and receiving which would be elevated to 
clear all obstacles, A form of ferrite circula- 
tor will be used to isolate the receiver and 
transmitter rf circuits. Such circulators are 
economical and provide up to 50 dB isola- 
tion but are quite critical as to proper 
termination. Damage to the antenna, for 
instance, which causes the swr to rise, would 
destroy the isolation characteristics. How- 
ever, that plan belongs to the future as well 
as the one to have the receiver bandwidth 
automatically controlled by the strength of 
the received signal — smaller bandwidths 
being used for weak stations to increase 
intelligibility. 

The Zugspitze DX repeater was installed 
in May of 1972 and has been fulfilling a 
repeater user's dream. Records will still be in 
the process of being set for some time as to 
how far away DX can be worked in the 
various countries the repeater signal covers. 
The debate also goes on as to whether DX 
via a repeater is really DX at all. But 
whatever might be said there is no denying 
that working various countries via a repeater 
couldn't be more fun. The Zugspitze re- 
peater will most certainly open up new 

thoughts and challenges for the usage of 
repeaters for years to come. 

. . .W2EEY 



OCTOBER 1973 



55 



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Tempo's Commercial Line VHF transceiv- 
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then compare prices. Your choice will 
have to be Tempo. 




TEMPO CL 146 

The CL-146 offers operation on the 146 MHz 
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• 12 channel capability • 13 watts or a power 
saving 3 watts » All solid state, 12 VDC • 144 
to 148 MHz (any two MHz without retuning) 

• Supplied with one pair of crystals • RF out- 
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• Provisions for external oscillator • Monitor 
feature • Audio output at front panel • Internal 
speaker * The Price: $279.00 



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As new as tomorrow! The superb CL-220 em- 
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220-225 MHz (any two MHz without retuning). 
At $329.00 it is undoubtedly the best value 
available today, 



TEMPO 6N 2 



The Tempo 6N2 meets the demand for a high power six 
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TEMPO imp 



Truly mobile, the Tempo/fmp 2 meter 3 watt portable 
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11240 W. Olympic Blvd., Los Angeles, Calif- 90064 
931 N. Euclid, Anaheim, Calif. 92801 
Butler, Missouri 64730 



AVAILABLE AT SELECT DEALERS THROUGHOUT THE U.S. 
56 



213/477-6701 

714/772-9200 
816/679-3127 



73 MAGAZINE 




James E. Taylor W20ZH 
1 25 7 Wild Flower Drive 
Webstei NY 14580 



BALANCED 



DIPOLE 



ANTENNA 



The antenna described displays I he /allotting features: rf balance to ground: 
lightning protection; low loss ground system: multi-hand capability: and 
simple erection procedure. 



Over the years I have erected a large 
number of 80 meter dipole antennas 
embodying a great variety of mechanical and 
electrical arrangements. Out of these multi- 
ple experiences have come a fair number of 
features which might qualify as "good" 
practice. 

It is the purpose of this article to describe 
a readily erected dipole system which com- 
bines excellent performance with unique 
electrical and mechanical features. 

First, I wanted the radiating efficiency to 
be high. Secondly, since the use of this 
dipole in a phased array was contemplated, a 
predictable dipole field pattern was desir- 
able. This required good electrical balance at 
the feed point and a uniform ground system. 

Third, since I have had enough good luck 
for one lifetime regarding lightning damage 
(none) I wanted the sides of the dipole to be 
directly connected to ground for dc at all 
times. 

Fourth, since I am addicted to antenna 
experimentation, 1 wanted the ends of the 
dipole to be readily accessible for length 
adjustment and the entire structure easily 
tp*ken down for major changes. 

In addition, why not add 40 meters? 

The principal radiation from such a di- 
pole is in a plane perpendicular to its 
direction; the polar plot of field strength is 
essentially a circle tangent to the surface of 
the ground. Thus, the radiation is concen- 
trated at the high angles, near the vertical. 



The desirable low-angle radiation will in- 
crease as the height of the antenna is 
increased- In addition, the losses in the 
antenna and in the ground are decreased as 
the height increases. 

An effective compromise between operat- 
ing results and cost of the installation 
normally calls for a height of about 40 to 60 
feet. Greater height is desirable but expen- 
sive, whereas at lower heights the efficiency 
and the pattern shape become unacceptable. 

It turns out that the five-section telescop- 
ing TV masts, available in the popular TV 
supply stores for about $20, are satisfactory 
for supporting the center of the dipole at a 
height of 45 feet. This mast can be assem- 
bled on the ground and walked up or hoisted 
to a vertical position. If clamped against a 
house or other structure at about the 15 
foot level the mast need only be guyed at 
the top, even in the strong winds of the 
Rochester area. 

The two halves of the 80 meter dipole 
serve as top guys in ? say, the north-south 
directions, and the two halves of the 40 
meter dipole (with a common coaxial feed 
line) double as east-west guys. 

For ease of erection the mast is pivoted at 
its base. This base support is a 5 foot length 
of 1-1/2" diameter galvanized steel tubing 
projecting I foot above the ground. A 5/16" 
bolt through the post and mast provides the 
pivoting shaft. The side of the mast is 



OCTOBER 1973 



57 



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58 



hacksawed diagonally at the base to clear the 
supporting post. 

The coaxial feed line for the dipoles is 
inside the mast; this decreases wind prob- 
lems and also serves to shield the outer 
sheath of the coax from unwanted rf coup- 
ling. 

A balun coil arrangement is frequently 
used to assure balanced currents at the 
center of a dipole antenna. In the present 
instance a novel method is used which not 
only provides the required balance to ground 
but which also offers a low-resistance dc 
current path to ground from both sides for 
lightning protection. 

The mast itself forms the outer conductor 
of a coaxial section having the sheath of the 
feedline at its inner conductor. The length of 
this coaxial section inside the mast is ap- 
proximately one quarter wave length. There- 
fore, if the shield is shorted to the mast at its 
base, the impedance viewed from the top 
will be high so that it can be connected 
across the center feed point of the dipoie 
without appreciable loading. This unortho- 
dox arrangement is completed by connecting 
the center conductor of the coaxial feedline 
directly to the top of the mast! One half of 
the dipole antenna is connected to this 
common point, the other half to the shield 
and, to relieve the suspense, it works fine! 
The arrangement provides dc current paths 
to ground for lightening protection of both 
sides of the dipoie and it achieves balance of 
antenna currents through its balun action. 

The rf transmitting currents in either half 
•of each of the dipoles are conveniently 
indicated by means of four flashlight bulbs, 
not shown in the figures. Each bulb is 
shunted across a 3 f1 length of the antenna 
wire just outside of the top insulator. A 3" 
length of #1 8 copper weld wire is used from 
each side of the bulb so that the latter i& 
soldered in place at a corner of a 3" 
equilateral triangle. This area of pick up loop 
gives adequate brillance for tests without 
burning out the bulbs. The equal brillance of 
the two 80 meter bulbs, for example, pro- 
vides an excellent indication of the* balun 
action of the unorthodox mast connection 
used. 

In order to insure a stable dipole pattern 
with symmetrical ground reflection and to 

73 MAGAZINE 



reduce ground losses, a grid of nine parallel 
ground wires, each approximately 200 feet 
long, spaced ten feet apart, was buried under 
the dipole parallel to its plane, A single 
cross-buss was placed across the middle of 
the grid and soldered at the cross-over 
points, The base support of the antenna 
mast was connected at the center of this 
ground system. 

The clamping hardware supplied with the 
mast was discarded. The mast was extended 
horizontally on blocks on the ground and 
the overlapping sections were secured against 
vibration by us of #18 self-tapping screws. 
The mast was painted to discourage rust; the 
color was chosen to match the shutters of 
the house in a gesture toward community 
harmony. 

The antenna wires and the coaxial feed 
line are supported at the top of the mast by 
a cylindrical plastic insulator. This insulator, 
which combines high strength with low wind 
resistance, is made by sawing off the grooved 
male portion of a 'T' fitting for plastic 
water pipe. There is a size which is a snug 
push fit over the 1-1/4" o.d. mast. The 
grooves serve to anchor the wires and they 
also provide an improved leakage path for rf 
currents. 

The details of the insulator assembly are 
shown in Figs, 1 and 2. All wires are #12 
stranded copperweld. The "D^-shaped wire 
loops pass through the insulator, one above 
the other, as shown. There are no screw 
connections to loosen or corrode and, of 
course, all connections are twisted and sold- 
ered. A radiator hose clamp holds the 
insulator in place. The RG-8/U coaxial feed 



SMALL JAR CAP CEMENTED I* PLACE 



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EAST 40 METER WIRE 




0- SHAPED WiR£ LOOPS 
THRU HOLES IN 
INSULATOR 



NORTH ao METER 
WIRE 



COPPEP BRAID 
SOLDERED TO MAST 
{GOES TO CENTER CONDUCT- 
OR OF COAX INSIDE MAST) 



I 1/4 M 00 MAST 



Fig. L Top insulator — side view. ^ 




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SPECIALS! CRYSTALS FOR 

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PI How To Use FM. A ■ 

comprehensive introduc- 1 
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peaters. The newest 
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wide, 

I Please send me the book(s) checked above. En- I 
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I Name 



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J Mail to: 73 Inc., Peterborough NH 03453 



Address 
City 



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ZIP 



eterborougn ritt UJ4DO 

■^M ^^^H ^^^W : ^^^™ ^^* ^^^* ^^^ ^^* ^* '^" 



OCTOBER 1973 



59 




Here's the book for every ham who 
wants to design and build a digital 
repeater control system (or who 
wants to just think about doing 
that). Contains sections on repeat- 
ers, basic logic functions, logic cir- 
cuit design, control systems, sup- 
port circuits, mobile installations, 
touchione, plus a special section on 
a "mini" repeater control system. 
224 pages. 

Hardcover $7.00 Paperback $5.00 



i — 



i u 



73 Magazine, Peterborough NH 03458 

Enclosed is $ Please send Dhard- 

cover ($7)/Dpaperback ($5) copies of 
Digital Control of Repeaters" to: 

Name Call 



I 



I 
i 
i 
i 
I 

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i State 



Address 
City 



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ZIP 



MAST 



SOUTH eO METER WIRE 



EAST 40 METER WIRE 




INSULATOR { PLASTIC PfFE ) 



INNER CONDUCTOR 



T 



UPPER DSHAPED WIRE LOOP 
THROUGH INSULATOR 



WEST 40 METER WIRE 



LOWER D-SHAPEO WIRE LOOP 
THROUGH INSULATOR 



NORTH 90 METER WIRE 
{ CONNECTED TO TOR OF 
MftST OUTSIDE 1 



Fig, 2. Top insulator - top view, 

line is supported from the 'TV-loops, cen- 
trally within the mast, (This feed line is cut 
to be a multiple of a half wave- 
length - approximately 82 1 2" for a 3 + 955 
MHz.) A noise bridge is used for this and all 
other resonance measurements. 

The mast was hoisted to the vertical 
position using an inexpensive 4-pulley rope 
hoist attached at the 16' height. After 
erection the mast was clamped to the house 
roof at the 15' level using a steel strap and 
lag screws. 

The four halyards at the end of the 
antenna wires are of 1/8" nylon rope. These 
are supported by 2-1/2" diameter galvanized 
posts seven feet high. These posts are each 
located at a distance of 80 feet from the 
base of the mast and are connected to the 
ground system. The ropes are secured by 
swivel snaps attached to the tops of the 
posts, for ease of lowering for antenna 
adjustments. 

The dipole was adjusted to resonance, 
using a noise bridge, by adding equal lengths 
at either end. Resonance was achieved at 
3.955 MHz with a length of 1 2CT 9" and an 
input resistance of 50^. 

The SWR of the antenna is quite low 
(approximately 1.01:1) and its response is 
sufficiently broad to cover the 80 meter 
phone band without appreciable decrease in 
signal strength. 

Results on the air have been excellent and 
it is a pleasure not to have to ground the 
antenna during lightning storms, 

. . ,W20ZH 



60 



73 MAGAZINE 



C. Warren Andreasen WA6JMM 
P.O. Box 2 926 D 
Pasadena CA 91105 





II I 111! 

H 



GENERATOR 



Probably one of the most used greeting 
or expression in amateur radio be it a 
car with call letter plates passing another, or 
the passing of an OSCAR satellite overhead, 
is the simple world, "HL" 1 do not know 
how it all started but I know that if I want 
to greet another ham on the road, I want to 
honk "HI." Therein lies the problem. My car 
is one with the horn incorporated in the 
steering wheel rim, and it is next to impos- 
sible to honk any kind of code, much less 
the rapid succession of four dots and then 
two dots. This prompted me to design a 
circuit which will digitally produce the word 
"HL W The scope of this article will be to 
describe the basic digital "HI" generator, 
which can be used in any application desired 
by the addition of the appropriate output 
keying stage- 
Figure 3 shows a typical output stage 
which can be used to key the horn relay of a 
car. In this application, the driver would be 
simply required to touch a momentary 
contact push button type of switch and the 
"HI" generator will start and self-complete 
the word "HI." This circuit uses a total of 
four integrated circuits and eight discrete 
components, and when built will easily fit in 
the palm of your hand. 

OCTOBER 1973 



Referring to Figs. 1 and 2, a unijunction 
transistor oscillator located on plug-in-board 

+SV +5V 



TO IC-4-1 




Fig. L "HI" generator. 



B 



-C>IC-3-l2 



UJT 
OSC 



FIG I 



3 t 




-3*9 



IC-4-10 



c-3-12 wv- 




II 



M 



74KJ7 



K R Q 



6 



START 
P8-I 



^'7 



K) 



) 



5 -i 




TO CB-l-5 



74K> ^&\ 



l 





4 A 

— C>TO IC-3H 



PUV 
TO IC-MI.40) 




B 



-OTOIC-3-2 



C 

— >TO IC-3-13 



■OT0C8H-9 



? — OTQCB-1-8 



CB-I-B 



A 4 74*0 *>& *v 




H4 74i0 
107 IC-3 



&^~ 




HI 



Fig, 2. Basic 'W generator. 



CB-I generates a timing pulse which is fed 
into a 7404 inverter (IC-4-1) and is shaped 
and inverted to form a narrow, negative- 



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going pulse. This pulse is fed into a JK 
flip-flop (IC-1) which, when allowed to run 
by the setting of the ^run" flip-flop, acts as 
a divide-by-two counter whose output is a 
symmetrical square wave. This square wave, 
which will be referred to as the clock term, 
is wired to two locations. The first location 
is the clock input of the SN7490 decade 
counter that "counts" the clock pulses, and 
the second location, the output gate, (IC-3) 
which uses the oppose phase or clock. This 
term is simply the Q side of the clock 
flip-flop. The purpose of the clock term 
driving one input of the output gate is to 
chop anything passing through this gate into 
a series of dots. Since this gate, as described 
thus far, will produce an endless string of 
dots, all we have to do is inhibit the 
unwanted dots and we will have the word 



CM 

IN4003 



+12-0V 



.270 
R5>l/2W 



FROM 
IC-3-6 





TDHORM 
RSJBf 



02 
2N5904 



04 
2N49t2 



Fig, 3, Typical output stage that will key the horn 
relay of your automobile. 



62 



73 MAGAZINE 



TIMING DIAGRAM 



ICH-3 CLOCK 



C-2-G 



IC-2-9 



IC-2-8 



IC-ZH1 




P^3WW^ 



X» INHIBIT 



O 
A 
B 

5 



2 3 4 



5 
A 

S 

c 



6 7 



S 9 k>wait 

OR 
RECYLE 

CL 

i 



"BEEP" OUT PUT INMI BIT- ( ABC) + ( ABC) + CLOCK* D 

_ OR_ 

OUTPUT - CUOCK- (ABC+ ABC + ABC + ABC+ABC+ABO-T5 

Fig, 4 m Timing diagram* 

"HP remaining. Referring to the timing 
diagram (Fig. 4) it will be noted that to form 
the word "HI" we must get rid of count 
zero, count five, and counts eight and nine. 
To do this we do not need to decode all bits; 
all we need is enough information to elec- 
trically describe the period we are interested 
in. You will see that count zero has a unique 
condition when terms A, B, and C are all 
low. These three terms are inverted by IC-4 
so as to provide the high level needed for the 
7410 to decode an AND condition of ABC 
In the same manner, the count of five is 
decoded using the terms A, B, and C, 



2N3053 



+ 12-IBV FROM 
AUTOMOTIVE 
SYSTEM 



t>+5V 




CR4 
IN4734 



Fig. 5* 5 V automotive power supply for the "HI" 
generator. 

Since we do not want counts eight or 
nine, we use the term "!>•* which occurs 
only during these counts, to directly inhibit 
them. A secondary function of this term is 
to reset the "mn" flip-flop back to the 
waiting state. So we can now say that we 
will have an output key unless clock is low 
or D is low or zero decade is present or five 
decode is present. Add this all together and 

all that is remaining is "HI." 

. . .WA6JMM 






YAESU 

Newly appointed dealer for the 
East Coast is now taking orders 
on Yaesu equipment. Send for 
literature and free list of used 
equipment available. 

FRECK RADIO & SUPPLY CO. 

40 Biltmore Avenue 

P.O. Box 7287 

Asheville, North Carolina, 28807 

Telephone: 704-254-9551, W4WL 



FM Schematic Digest 

A COLLECTION OF 

MOTOROLA SCHEMATICS 
Alignment, Crystal, and Technical Notes 

covering 1947-1960 
136 pages ir/ 2 "x 17" ppd $6.50 

S. Wolf 

Box 535 

Lexington, MA 02173 



NEW 

MX1A 

$47.50 



NEW 



NEW 



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MINI-MIXER 



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This is a plug in unit to replace the first mixer 
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but the strongest (next door) cross modulation 
in the S line. It uses the latest in FET design. If 

not satisfied, money refunded. 

Designed Built Backed 

by . . . . 
ANTENNA MART 

BOX 7 RfPPEY, IOWA 50235 



>v 



Isolated - Pad - Drill - Mill 

Precision circuit board construction 
without etching. Fits hand drill, e lee- 
trie drilL Simple, fast, economical, 
safe. Sizes: .250, ,160 dia, 

$6.95 ea. 
Calif, residents add 5%. 

A F STAHLERCo 

PO BOX 354 CUPERTINO, CALIF 95014 





THE MILLIWATT 



r ah about underdve watt amateur radio ** r 
If you've bftin wanting to try QRP. then The MMMwatt is a 
MUST for you!" 

• Conn ruction Project* • Technical Article* 

• Operating News • WAS fc QRPP OXCC Standing* 

RATES: $3 40 yaarly. Reprint*. Vol. I— $4.00; II «* III— S3 SO 

each (all three-t10 00> Sample 254 

SUBSCRIPTIONS, to: ADE W £| 5S KiMG/g 
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OCTOBER 1973 



63 



— — 



available 

The exciting all new 

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rem 



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TAKE A SLICE OUT OF THE FUTURE . . 

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Feature- wise . . . the IC-230 is fully synthesized (with the new exclusive "Phase 
Lock Loop System") . . . all modular construction (servicing is a snap— in and out) 
. . , a receiver that is very sensitive and selective as to what it hears (better than 
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. . . plus a super E filter mosfet front end, making copy a pleasure. 

* And not a crystal to buy with the exclusive "Phase Lock Loop System'*, 
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- GRAB HOLD OF THE IC-230 AT YOUR LOCAL DEALER TODAY - 



Distributed by: 



ICOM 



— Dealerships Available 



ICOM WEST, INC. 

1251 ■ nOrti St N.E. 
Beitevue, Wash 98008 
(2061 641 0554 



ADIRONDACK 
RADIO SUPPLY 

185 West Mam Street 
Amsterdam. NY. 12010 



ICOM EAST 

Dn ACS. I^c 

Box 331 

Richardson. Tex 75080 

12141 235*0479 



64 



73 MAGAZINE 



Get the entire 
Inoue ICOM family 
at one of the dealers 
listed below: 



ALABAMA 

Wolfe Electronics 

Sox 358 

Foley, AL 36535 

ARKANSAS 

Gavin Electronics 

516 Rrdgeway 

Little Rock. AR 72205 

ARIZONA 

Ell Dee Enterprises 
12612 N, 28th Dr. 
Suite 3 
Phoenix, AZ 85029 

CALIFORNIA 

Alpha Sound 

1 405 Dry Creek Road 

San Jose, CA 95125 

CDS Electronics & Hobbies Unltd. 
235 Mitchell Drive 
Atwater, CA 95301 

Electro Service 

240 Main Street 

San Mateo, CA 94401 

ICOM FM Sales 

6234 A, Fountain Blvd. 

Hollywood, CA 92023 

Henry Radio Company 
1 1 240 W, Olympic Blvd. 
Los Angeles, CA 90064 

Selectronics 

1709 Markston Road 

Sacramento, CA 95825 

Sequoia Stereo 
773 -8th Street 
Arcadia, CA 95521 

Sichel Equipment Co. 
245 E. Harris Avenue 
5, San Francisco. CA 94080 

COLORADO 

LEC Electronics 
P.O. Box 7515 

Pueblo West, CO 81007 

FLORIDA 

Amateur Electronic Supply 
621 Commonwealth 
Orlando, FL 

Goldsteins 

Box 3561 

Pensacofa, FL 32506 



ILLINOIS 

Ertckson Communications 
4653 N. Ravenswood 
Chicago, IL 60640 



INDIANA 

Story Electric 
2039 Fairfield Ave. 
Fort Wayne, IN 

Story Electric 
441 Walnut 
Wabash. IN 

KENTUCKY 

Everhari Electronics 
116 Sydney Street 
Lexington, KY 

MARYLAND 

COM Electronics 
900 Cram Hwy. S.W. 
Glenn Burnie, MD 21061 

MEXICO 

NOVO Mex 
Antonio de Mendoza 
N°320 Lomas 
Vlextco 10, d.f.* Mexico 

MONTANA 

Conley Radio Supply 
405 North 24th 
Billings. MT 59101 

NEW MEXICO 

Robert Foster 

Box 198 - Escaboss Star Rt 

Tijeras, NM 87059 

NEW YORK 

R.E. Nebel Laboratories 
31 Whitehall Blvd. 
Garden City, NY 11530 

Barry Electronics 

512 Broadway 

New York, NY 10012 

NORTH CAROLINA 

Vickers Electronic Supply 
506 6. Mam St. 
Durham. NC 

OHIO 

Amateur Electronic Supply 
17929 Euclid 
Cleveland, OH 

H & C Electronics 
6271 Hammcll Avenue 
Cincinnati, OH 45237 

OKLAHOMA 

Blacks Radio Company 
413 N.E. 38th Terrace 
Oklahoma City, OK 73106 

Roland Radio Company 
5923 E. 31st Street 
Tulsa, OK 74114 

OREGON 

Portland Radio Supply 
1234 S.W, Stark 
Portland, OR 



PENNSYLVANIA 

Harntronics 

4033 Brownsville Rd, 

Trevose, PA 1 9047 

Kass Electronics 
2502 Township 
DrexeL PA 19026 

SOUTH CAROLINA 

Accutek 

420 Laurens Rd. 

Greenville, SC 29607 

Electronic Systems Inc. 
1518 Gregg Street 
Columbia, SC 29201 

TEXAS 

Bellaire Electronic Supply 
5204 Bellaire Blvd. 
Bellaire, TX 77401 

Electronic Center, Inc. 
2929 N. Haskell 
Dallas, TX 75204 

Trimble Electronics 
1913 Mary Ellen 
Pampa, TX 79065 

UTAH 

Utah FM Sales 

1365 E. 5360 So, 

Salt Lake City, UT 84117 

VIRGINIA 

Northern Virginia Communications 
729 N. Edison 
Arlington, VA 22203 

WASHINGTON 

ABC Communications 
17541 - 15th N.E, 
Seattle. W A 98155 

ABC Communications 
2002 Madison Avenue 
Everett, WA 98200 

Eichmeyer Electronics 
Box 691 - Route 1 1 
Spokane, WA 99208 

N.H.E, Communications 
151 12 S + E. 44th 
Bellevue, WA 98006 

Progress Electronics 
852 Commerce Street 
Longview, WA 98632 

WISCONSIN 

Amateur Electronic Supply 
4828 Fond Du Lac Ave. 
Milwaukee, Wl 53216 



IF YOUR DEALER DOESN'T STOCK 

/COM EQUIPMENT, 

LET THE tCOM DISTRIBUTOR 

FOR YOUR REGION KNOW, 



OCTOBER 1973 



65 






GREGORY ELECTRONICS CORP, 

The FM Used Equipment People. 

243 Route 46, Saddle Brook, N. J. 

Phone (201)489-9000 



GENERAL ELECTRIC 

VOICE COMMANDER 








SEND FOR NEW 
1973*/2 CATALOG 




Full Solid State FM Transmitter-Receiver 

132-150 and 150-174 MHz/Size: 9.5' * 5.3" x 1,7" 

1 watt output, .5 micro-volt sensitivity. 

High performance, completely self-contained two-way 
FM radio, Compact, lightweight easily operated and 
hand-carried. Housed in high-impact, 2-section case. 
All external hardware polished stainless steel. Top 
section has transmitter and receiver modules, built-in 
mike and speaker, antenna, carrying handle, all 
switches and controls. Bottom section has battery 
power supply. Power connections to top section made 
by plug and jack connection. 



$ 



138. 

Crystals and tuning, add $50. 

Proper chargers available 
separately, each $15. 



Includes rechargeable 
nickel cadmium bat- 
tery pack and charger 




Lots of 5 less 10% - $124.20 
Lots of 10 less 15% - $117,30 



TWO METER MOBILE UNITS 

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74" or 17" case, complete accessories, fully narrow band. 



MT/33, 12 volt, 30 watts, transistor 
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MA/E33, 6/12 volt, 30 watts, vibra- 
tor power supply 4iJ?R 

with wide band receiver 



^ 



$73. 




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66 



73 MAGAZINE 




Martin Weinstein 
414 D Kiefaber 
Dayton OH 45409 




R 



ATHR 

OSCILLATING RING 
WITH 

INDICATING SHIFT REGISTER 



In past months amateurs have swung to an 
increasingly large-scale utilization of digi- 
tal circuitry in the myriad of applications 
borne by the creative inventiveness inherent 
to the minds of lazy men. Finding an easier 
way to get the job done is a cardinal rule 
among amateurs which often, alas, requires 
staggering amounts of brainpicking and mid- 
night oil burning. 




Being a newcomer to the digital circuitry 
field, I diligently applied myself to the job 
of relearning an old hobby. It was in the 
midst of one of these study sessions that it 
occurred to me that a venture into an 
interdisciplinary approach could be profit- 
able. 

My friends, if you think this a fiction 
penned by somebody's relative from 
"Feenix, Arix," please bear with me, I am 
going to describe an amazing circuit shortly, 
but I feel there is much to be learned from 
the kind of thinking that led to its discovery. 



The radio circuits developed in vacuum 
tube days are mostly analog devices produc- 
ing unquantized outputs (on a macroscopic 
scale) proportional to their inputs. One of 
the greatest tools ever developed for analog 
circuits was the concept of feedback. 

Feedback gave us greater sensitivity in 
our detectors when we made them oscillate; 
remember the old super-regenerative rigs? 
Another form of feedback led us to develop 
automatic everything control circuits. And 
do you remember reflex amplifiers? 

Negative Amplifiers 

Circuit designers applauded the develop- 
ment of the tunnel diode because it exhibi- 
ted a negative resistance region. Fifteen 
years ago the easiest place to go for a 
negative resistance region was a neon lamp. 
In addition, we could make neon bulbs 
sensitive to ac, dc, rf, Light levels, static, 
radiation, or body capacity. And an NE-2 is 
a pretty compact little unit. 




OCTOBER 1973 



67 



By taking advantage of the negative resis- 
tance region of the NE-2 in digital circuitry, 
we can design into a simple ring counter of a 
few stages many of the sensitivities of the 
neon bulb if we correctly choose our oper- 
ating parameters. We can further sensitize 
the circuit by many of the tricks we learned 
in analog days: oscillation, feedback and 
reflexing. Further, we can sensitize and 
balance the stages to the point where en- 
vironmental factors can influence the be- 
havior of the active elements, warping the 
count, And finally, since the neon bulb is 
kind enough to glow for us at certain 
segments of its nonlinear operation, we can 
utilize it to indicate visually when shifting 
occurs. 

The Circuit 

The schematic for the three-stage oscil- 
lating ring counter with indicating shift 
register that resulted from my experimenta- 
tion is shown around here somewhere. A 
simple line -op era ted half wave rectified 
power supply is included for simplicity and 
ease of operation. Rl is a current-limiting 
resistor to prevent damage to the NE-2s and 
to help make the counter balance less 
critical. 



^^^^^ 



A-/VA 



v_ 



) 



_L 



A*W 





Fig, 2, All components were mounted on one side 
of a small (1W T x 1%") piece of perf board. All 
wiring was done on the bare side of the board, 
using sleeving where needed. 

The simplest test of the circuit is to 
assemble it and attempt operation at room 
temperature under normal lighting and radia- 
tion conditions. A properly -operating unit 
will flash in a sequence of 
2-1-2-1-2-3-2-1 -2-1-2-3. 



117 
VAC 




• NE-2 



Fig. I. Schematic diagram of the TSQRC/ISR. 



CI is included to slow the circuit shifting 
to a reasonable rate and to help, or at least 
to try to help, prevent the circuit from 
running away as it oscillates in and out of 
balance. 

Match the three remaining 1 meg resistors 
fairly closely, I got away with using 5% 
off-the-shelf units. The lamps should be 
matched and mounted adjacent to one 
another, with the six electrodes aligned. 



Once the correct pattern has been estab- 
lished, age the unit by allowing it to operate 
unattended for about thirty hours. During 
this time, the kids will get a big kick out of 
watching the lights blink. 

After aging, the unit is ready to function 
as a eutectic digital-human interface device, 
not dissimilar to Spock's Tricorder on the 
fictional program Star Trek. Readout is by 
means of variation in the basic flash pattern. 

The TSORC/ISR, despite its tremendous 
versatility, has no capability for memory, as 
do its big second counsins at IBM. Although 
I have explained its operation rather fully, 1 
have not dealt with the problem of program- 
ming the unit If I receive enough requests, I 
will include a short article on the program- 
ming of the TSORC/ISR in a subsequent 
issue. 



, . .Weinstein 



63 



73 MAGAZINE 



FREQU 




Bill Hoisington K1CLL 
Farover Farm 
Peterborough NH 03458 




THE 



EASY WAY 



Multiplying to 2m with transistors is easy if you take the correct precautions. 



This article is not only a construction 
article but also explains some of the 
things that can happen when you set out to 
build a frequency multiplier from scratch. 

You might say multipliers are easy be- 
cause you don't have to worry about feed- 
back when the input is on a different 
frequency than the output. True enough, 
but that's not all the story. Let me quote 
from RCA's Transistor Manual SC-14 tfre 
chapter on frequency multiplication: 
"Various types of instabilities can occur in 
transistor frequency multiplier circuits, in- 
cluding low-frequency resonances, para- 
metric oscillations, hysteresis and high fre- 
quency resonances." Hysteresis refers to 
discontinuous mode jumps when either the 
input power, frequency, or both, is increased 
or decreased- And, "The transistor may 
behave as a locked oscillator on the funda- 
mental frequency." Further, on VHF or 
wide-band circuits, "Unless the builder has 
had considerable experience with these types 
of circuits, he should not undertake the 
construction of such items." That's all very 
well and true to an extent, but it h the same 
old story; how are you ever going to get that 
experience if you don't make a start? So 



RF EN 




L2 



Fig, L Schematic of trouble circuit. (Do not 
build,) 



here is some help, After half a century in 
radio I am still learning every day (pretty 
poor day when you don't) and this is what 
Pve already learned this year about frequen- 
cy mul tip hers: 

The project calls for high gain because 
you Ye out for power while multiplying. It is 
always pleasant if you can get it. The more 
power you have in each stage, the less liable 
you are to have reaction or feedback into 
that stage from the final output stage. This is 
very important when you try for power like 
25 W, and some people are already working 

on 500W output power on Two! 

A two-stage IC FM modulated, low-power 

source was used to drive the input on 24.5 
MHz. This oscillator's output was kept low 
for stability -purposes, which didn't make 
things any easier to start with, but it is now 
working very well. The whole project de- 
livers some 1 — L25W output on 147 MHz 
with good, smooth and easy tuning — no 
jumps or other troubles. 

Figure 1 shows the complete multiplier 
circuit first as a guide, because in the past 
some readers have built a wrong circuit that 
was illustrated to show what not to do. 
Figure 1 is one of these. Troubles which 
occurred during design work are thus shown 
in Fig. 1. Do not build this circuitl The first 
thing I did was to use the wrong transistor. I 
have several new, "hot" types, so of course 
in they went! You need high gain — go 
ahead! Trouble and plenty of it showed up 
right away* Now this is a perfectly good 
circuit and can be found in most manuals. 
But* a fantastic set of unwanted spurious 
oscillations showed up which clobbered the 
oscillator drive, and Ql took off on its own, 



OCTOBER 1973 



even with the drive removed. After fighting 
it for a day or so, putting in a trimmer for 
CI and changing transistors, it was better, 

but finally I found the cause: The lower half 
of LI (in Fig. 1) from the tap to the cold 
end resonated beautifully and maddeningly 
with CI and the base of Ql, producing a 
base-tuned collector oscillator on 147 MHz. 
This is not a good circuit even when used 
intentionally. 

The Cure 

This also is not a "new" circuit, the idea 
being to show when to use one or the other 
in order to do the right thing the first time. 
At 73 we try to help, because in our society 
today there just isn't all that time available, 
and this little story can save you some of 
that precious time. Putting a large capacitor, 
C3, from ground to base is the solution. 
Then the base of Qi does not resonate on 
147 MHz, and C3 also acts as a low pass 
filter unit to stop oscillation at 147 MHz. 
The incoming 24,5 MHz is resonated by LI 
an^l C2, now referring to Fig, 2, the correct 
schematic, with the ratio of C2 and C3 
dropping the impedance down to match the 
base of QL C3b is added to C3 for this 
purpose. You will find the tuning with C2 
and the matching with C3 to be very 
smooth- Ql is a 3866 which is always a good 
multiplier and does a good job up to 450 
MHz. In this case it is used as a tripler to 
73,5 MHz. I can assure you that it or the 
Motorola equivalent (for medium power 
usage), the HEP 75, will always do a good 



job of multiplying for you — all the way to 
450 MHz. The collector of Ql is connected 
to the top of Ll ? which is tuned to 73.5 
MHz by C4 S with C5 matching into the base 
of Q2 in the same manner as the input to 

QI- 

An rf choke coil is added to the base of 
Q2 to keep the gain up. No plus voltage was 
needed on the base as there is plenty of drive 
from QL Always check this to be sure. No 
emitter resistor was needed either. Be sure to 
check this, too! I always have a lot of 
external pots lying around, 500, 5,000 and 
5 0K ? and lots of clip leads for them. Very 
useful. Q2's collector output is tapped down 
on L3, as these 3866\s have a low collector 
impedance when being pushed for output, 
which is what we are doing here. The 
output, tuned to 147 MHz by C6 and L3, is 
also tapped down on L3 and matched to the 
cable by CI. There is about 200 mW of rf 
here, which lights a No. 48 bulb nicely. You 
will find the circuit as shown in Fig. 2 is very 
smooth in tuning and reliable, and will 
handle 1 or 2 MHz without retuning. 

The 1W Amplfier 

With 1W you can begin to talk through 
several repeaters in your area, so we put a 
little time in on an amplifier for this 
purpose. Figure 3 shows this unit with a 
2N5913 RCA transistor, one of their newer 
and livelier devices designed for this work, A 
cable input is shown, but this may be 
eliminated along with either C7 of Fig. 1 or 
CI of Fig, 1 , as the two series capacitors are 



+ 12 



RF input 

24.5 MHz 

LOW POWER 



C2 

7-100 pf 



Ql 

HEP 75 
-^£— I ?5K OR 



CI 
Jl 4-25pF 




+ 12 

Q 



220 



L2 



C4 

3-40 pF Q2 

xl ^ HEP' 

■#-. OR 



C5 
7-IOO pF 



,01 




L3 



> \ * i < 

io-iaopF i 0<: 



Ih 



Fig. 2, Schematic of the 25 to 147 MHz multiplier. 
LI — 20 turns No. 26 on 0.5 cm diameter form, 
length 1 cm. tap at center; L2 — 8 turns No. 22 on 



form 0.8 cm diameter, winding is 0.8 cm long; 
RFC — 25 turns on form 0.5 cm diameter, 1.8 cm 
long. 



70 



73 MAGAZINE 



m 



COMMUNICATIONS 



HAL ID-t REPEATER IDENTIFIER 




vjy : •:.. .-. :'.- 






• 




Circuit board wired & tested 
With rack w/cabinet 



■ ■ 



. $75.00 
$115.00 



TTL logic. Power line frequency counter for 3 
minute or less timing and control Easily re- 
programmable diode ROM uses only 27 diodes 
(depending on call) ttfsend DE "any call". Low 
impedance audio with volume and tone control. 
All circuitry, including PS on small G10 glass PC 
board. Write for full details. HAL COMMUIMI 
CATIONS, Box 365L, Urbana IL 61801 



HI 



HOT CARRIER DIODES 

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LINEAR IDS: 

DIGITAL ICS 
MRU 




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DIP TTL 7400 749T 7402 74 1 D 7420 7430.1440 S 48 

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MANY DTHER DEVICES AND COMPONENTS IN STOCK.WfllTE FDR CATALOG 



FERROXCUfiE FERR1TE HEADS . 10/S1.25 
10 ICS, 16-DIP S 70 



HAL COMMUNICATIONS 

Box 365 L. Urbana I L 61801 • 217-359-7373 



Center £ Electronic World 



h ^.f rs\ r & ^-.JlO 

& $ W 



VHF PRE AMP 

100 to reOMHr 
25 db gain 

2.6 db noise figure 
SO ohm input and 

output impedance 
Price $29.95 






VHF CONVERTER 
TOO to 160 MHz 
2.5 db noise figure 
SO ohm input impedance 
Better than A uv sensitivity 
30 db gain 
Price S59.50 



Q-TR0N]C5j 



FREG. PRESCALER 

Up to 250 MHz 
Available assembled, o* 

kit form 

frtfe $96.50 a ssemhlml 
S69. 50 kit 



WANTED - HAM 



With General Class License or better to manage 
amateur radio R esU me to: 

C. J. Harrison 
Hatry Electronics 
500 Ledyard Street 
Hartford, Connecticut 06114 



depa rtment. 
No phone calls 
— by appoint- 
ment only. 



^ 



Q-TRONICS 



310-8 So. Meadow Lane 
Golden Valley, Minn, 55416 









S 



^ 






\-'- • - -y.^TtlQ. • VA^^EV^U' ~3*w"*-^fc 4V 



* 



C2 

7-100 pF 



INPUT 
24,5 MHz 

200 v 

MILLIWATTS \ — l 




4 



NO, 40 

I WATT 



fe 



o+rs 



Fig, 3, 2 meter FM amplifier that wUl deliver 1W output. LI — B turns No. 20, 0.8 cm diameter, 2 cm 
long. Input tap at Wz turns from low end; LI — same as LI with collector tap at VA turns and output 
tap at 2 turns from the low end; RFC — 25 turns Wo. 30, on phenolic form, 0.5 cm O.D., 1.8 cm long. 



not needed together. The base of Ql in Fig. 
3 is treated in the same way as the multi- 
plier, and responds equally well — C2 and C3 
being the impedance matching network. 
While not critical, the best power output is 
obtained at the correct tap. I used a No, 40 
lamp for a 1 W load through C5, and this can 
be lit to about 1.25W brilliancy with every- 
thing working right. Even though the 
2N5913 is a pretty hot item, when loaded it 



handles well without self-oscillation and 
does a great job. 

Conclusion 

So here is a good straightforward project 
which is very handy to have around, I use it 
for transmitting exactly 600 kHz lower than 
the receiver in combination with a 1 0.1 MHz 
crystal. But that is another story . . . 

. . JC1CLL 



OCTOBER 1973 



71 



INTERNATIONAL ELECTRONICS UNLIMITED 



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Linear* 
LM300PoaVreg 

(super 723 V)T05 $ .95 ea 

LM301 Hi performance ampl TQ5 ,45 ea 

LM3Q2 Voltage follower T05 .95 ea 

LM304 Neg Volt regulator T05 1 25 ea 

LM305 Pos Volt regulator T05 1 .25 ea 

LM3G7 Op Amp (super 741 1 TOS .45 ea 

LM308 Micro power Op Amp TOS 1.25 ea 
LM3Q9K 5V 1 A power supply 

regT03 1.95 ea 

LM309H 5 V regulator T05 1.25 as 

LM310 Volt follower Op Amp TOS 1,45 ea 

LM31 1 Hi perf volr^omp T05 1.25 ea 

LM320 5.2V Neg regulator T03 1.95 ea 

LM32Q 12V Neg regulator T03 1.95 ea 

LM320 15V Meg regulator T03 1 95 ea 

LM3B0 2 watt audio amplifier Dip 1 .75 ea 

LM3900 Quad Amplifier Dip 50 ea 

LM709 Op Amp T05 or Dip .29 ea 

LM723 Volt reg. Dip .75 ea 
LM741 Comp Op Amp TOS-Dip 

10/S3.95 .45 ea 
LM747 Duel 741 Op Amp Dip 

4/53,50 .95 ea 
Phase Locked Loops 

NE565 Phase locked loop dip £2.95 ea 

NE566 Function Gen TOS-mmi dip 2.95 ?l 
NE567 PLL/Tone Gen TOS mini dip 2.95 ea 



LED 



MV10B Visible red SUPER SPECIAL .25 ea 
MV50 type red emitting 25 ea or 5/ 1 .00 

MV 5020 type Large red .35 ea Of 3/1.00 

ME4 Infra red T0 18 ,69 ea 

MAN 1 The Original 4.25 ea 

MAN 3 type 1 .95 ea, 3 or more 1 ,49 ea 

MAN 4 type 2.75 ea, 3 or more 2,50 ea 

Data Lite 707 (MAN 1 repli 4.25 ea 



Opto Isolators 

MCA 2-30 Darlington 
MCD 2 Diodes 

MCT 2 Transistor 



.95 ea 
L95 ea 

1.45 ea 



Memories — Are Made Of — 
1101 256 Bit RamMos (2501) 
1103 J 024 Bii Ram Mos 
74BP 64 Bit Ram TTL 
0223 Programme Rom 

Data Included wiiri Memories 



2.95 ea 
7.95 ea 
3,25 ea 

5 9S ea 



MOS Shift Registers - Limited quantities 

2506 Dual 100 bit dyn. shift reg, (mini) .30 ea 

2509 Tristate dual 50 bit st, shift reg. .30 ea 

2510 Tristate dual 100 bit st. shift reg. .30 ea 

251 1 Tristate dual 200 bit st. shift reg. ,30 ea 

2518 Hex 32 bit static shift reg, .30 ea 

2519 Hex 40 bit static shift 2519 Hex 40 bit static 
shift reg. .30 ea 

2521 Dual 128 bit shift reg. (mini) .30 ea 

2522 Dual 132 bit shift reg. (mini) .30 ea 

2524 51 2 bit recirc, dyn. shift reg. (mini) .30 ea 

2525 1024 bit recirc, dyn. Shift reg. (mini) ,30 ea 
2527 Dual 256 bit static shift reg. {mini) .30 ea 
Assortment of any 2500 IVIOS items 4/1,00 

NOTE: 2500 series MOS shift registers ere factory 
seconds & have not been re-screened. 



Calculator Chips 

5001 LSI (40 pin) Add, subtract, multiply & 
divide 12 digit 

Data supplied with chip 6.95 ea 

Data onfy Refundable Wpurchase TOO ea 

5002 LSI Similar to 500t except designed for 

battery power 

Data supplied with chip 8.95 ea 

Data only- Refundable w/purchase 1.00 ea 
5005 LSI (28 pin) Full four function mem- 
ory, 12 digit display and calc.7 segment 
multiplexed output 

Data supplied with chip 10,95ea 

Data only ■Refundable w/ purchase 1 .00 ea 

Digital Clock . . , on a Chip 

MM531 1 (28 pin) Any readout 6 digit BCD, 
with spec sheet 1l.95ea 

MM 531 2 (24 pin) Any readout 4 digit Ipps 
BCD, with spec sheet 8,95 ea 

MM 531 4 (24 pin)LEDIncandescent readout 
6 digit with spec sheet I0.95ea 

MM5316 (40 pin) Normal alarm, snooze 
alarm, sleep timer 12 or 24 hour operation, 
with spec sheet I5,95ea 



Grab Bag Specials 

15 Assorted DTLs (dip) 
15 Assorted TTLs (dips) 
NOTE: Factory seconds, not tested 



1,00/bag 
1 ,00/bag 



Satisfaction guaranteed. All items except as noted are fully tested. Minimum order $5.00 prepaid in 
US and Canada. California residents add sales tax. Orders filled within 3 days after receipt. Please add 
$.50 per spec sheet for items priced at less than $1.00 each. 

INTERNATIONAL ELECTRONICS 



UNLIMITED 



P.O.BOX 1708 S 



MONTERY, CA 93940 



72 



73 MAGAZINE 





Would you believe that there are some of us who remember when 73 
Magazine was only 374 a copy? (How time does fly!) 

At the present time our subscriptions are increasing over 1,000 per 
month and we're beginning to realize that 1973 is our year (obviously). 

In order to further accelerate this trend, we're rolling back the 
calendar . . . yes, back to 1960 . . . and 374 a copy. We realize that we 
cannot get rich this way, but who cares when you can make so many 
subscribers happy! 

Now . . . for a limited time only ... (until we regain our 
senses) . . . you can subscribe to 73 for only 314 a copy on a 3-year 
subscription. That's only $13.32 for 3 years. 

Subscribe NOW and have it end in '76. That's the spirit! 




The regular newsstand cost for 3 years is 
$36.00-subscribe Now and save $22.68. 



Q New Su bscrip tion 
^Renewal or extension 



□ 



Order Form 

73 Magazine 
Peterborough NH 03458 USA 



3 y rs, $1 3.32 



10-73 



1 yr f $6 



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Fascinating World of Radio Communications 

Novice Class Study Guide 

General Class Study Guide 

Advanced Class Study Guide 

Extra Class Study Guide, reduced price . 

VHF Projects for Amateur & Experimenter 

VHF Antenna Handbook 

How to Use FM, an introduction 

FM Repeater Atlas, worldwide w/maps 

*FM Repeater Circuits Manual 

* Digital Control of Repeaters, new 

RTTY Handbook, radio teletype A to Z 

ATV Anthology, fast scan VHF TV 

*SSTV Handbook, new, only slow scan avail 

Diode Circuits Handbook, galore 

73 Transistor Circuits, all useful 

Transistor Projects, mucho 

Solid State Projects 

IC Projects v 

108 Q & A, transmitting, receiving, ant 

TVI Handbook, why suffer 

Coax Handbook, cables & connectors 

DX Handbook, w/map 

World DX Map, wall size, rolled 

Custom DX Bearing Charts, beam headings 

U.S. Maps, for WAS, etc (4 ea) 

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*Hardbound versions available @ $2.00 more. All items postpaid. 



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, m 




GTX-2 

30 WATTS OUTPUT 




GTX-200 

30 WATTS OUTPUT 



2 meter FM Transceiver 

(1) GTX-2 (built-in DC PS) and 04/Q4 «. 249.95 

(3) AC POWER SUPPLY $49.95 

(3) 2 Extra, crystals your choice (stock list) ..«.•• SI2.00 

REGULAR $311.90 
OUR SPECIAL PACKAGE PRICEI $249.95 



GTX-10 

10 watts output 

Simple conversion 
to 30 watts output 




10O% AMERICAN 
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Write for special deal! 

Regency, Midland, Gladding 25, SBE, etc., 
also in stock. Please write for quote 



ll) etianjtels in QTX-2 & CTX-Ki with ]4G.!M/I4fi.04 Included- 
Three pole low pass (titer on both transmit and receive. 1 watt 
low power position, Provision Uit tone eiicptler, Simple internal 
snapping provision allows imilti -channel u^e of tiny crystal in 
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supplied. <M0 (SLASH KOAItDS. Professional level construction 
by (tUtinifuLshecl Avionics Mfg. — General Aviation Electronics* 
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amp** Transmit: High ii.ll pjttiptt* Low: 1.7 amps, Made in U.S.A. 



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Alpha-70 Pfl,-70V vapor cooled linear. 

b rand new conri 
AMECQ 
Tfc-626fli Imsler xrritter w/ti2l VFO. 

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TX-626& Jmetef Knitter 
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43 wati meters [new! Imw ted quant ny 
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£25 1 VHP canu. 
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OCTOBER 1973 



75 












**•*•*«„ 






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results - write me 
your needs. 



Galaxy 



76 



73 MAGAZINE 



CC RULES 

AND REGULATIONS 

PART 97 (V) 



J 



CONTENTS THIS MONTH 

Subpart D — Operating Requirements and 

Procedures 

General 
Sec. 

97.77 Practice to be observed by all licensees. 

$7.79 Control operator requirements, 

97,81 Authorized apparatus* 

97,83 Availability of operator license. 

97*85 Availability of station licen&e, 

97,87 Station identification. 

97.89 Points of com muni cation a. 

97.91 One-way communications. 

97,93 Modulation of carrier. 



Cbntinuing from last month the complete 
text of the FCC Rules & Regulations 
pertaining to the Amateur Radio Service* 



SUBPART D— OPERATING REQUIREMENTS 

AND PROCEDURES 

General 

§ 97.77 Practice to be observed by all licensees. 

In all respects not specifically covered by these regu- 
lations each amateur station shall be operated in ac- 
cordance with good engineering and good amateur 
practice* 

§97.79 Control operator requirements, 

(a) The licensee of an amateur station shall be 
responsible for Its proper operation, 

(b) Every station when in operation shall have a 
control operator at an authorized control point. The 
control operator may he the station licensee or an- 
other amateur radio operator designated by the licen- 
see. Each control operator shall also be responsible for 
the proper operation of the station. 

(c) An amateur station may only be operated In the 
manner and to the extent permitted by the operator 
privileges authorized for the class of license held by 
the control operator, but may exceed those of th^ sta- 
tion licensee provided proper station identification 
procedures are performed, 

(d) The licensee of an amateur radio station may 
permit any third party to participate in amateur radio 
communication from his station, provided that a con- 
trol operator is present and continuously monitors and 
supervises the radio communication to insure com- 
pliance with the rules. 

O #7*70 headnote and text revised eff* 10-17-72 f and 
(d) further revised etf, 12-1-12; FI(7£)-iJ 

S 97.81 Authorized apparatus. 

An amateur station license authorizes the use under 
control of the licensee of all transmitting apparatus 



at the fixed location specified in the station license 
which is operated on any frequency, or frequencies 
allocated to the amateur service, and in addition au- 
thorizes the use, under control of the licensee, of 
portable and mobile transmitting apparatus operated 
at other locations. 

§ 9733 Availability of operator license. 

The original operator license of each operator shall 
be kept in the personal possession of the operator while 
operating an amateur station. When operating an 
amateur station at a fixed location* however, the li- 
cense may be posted in a conspicuous place in the room 
occupied by the operator. The license shall be avail- 
able for inspection by any authorized Government of- 
ficial whenever the operator is operating an amateur 
station and at other times upon request made by an 
authorized representative of the Commission, except 
when such license has been filed with application for 
modification or renewal thereof, or has been mutilated, 
lost or destroyed, and request has been made for a 
duplicate license in accordance with f 97.57, No recog- 
nition shall be accorded to any photocopy of an opera- 
tor license; however, nothing in this section shall be 
construed to prohibit the photocopying for other pur- 
poses of any amateur radio operator license, 

197.85 Availability of station license. 

The original license of each amateur station or a 
photocopy thereof shall be posted in a conspicuous 
place in the room occupied by the licensed operator 
while the station is being operated at a fixed location 
or shall be kept in his personal possession. When the 
station is operated at other than a fixed location* the 
original station license or a photocopy thereof shall 
be kept in the personal possession of the station li- 
censee {or a licensed representative) who shall be 
?resent at the station while it is being operated as a 



OCTOBER 1973 



77 



GATEWAY 

ELECTRONICS 

8123 25 PAGE BOULEVARD 

ST. LOUIS, MISSOURI 63130 

(314) 427-6116 



Fig. A 




Fig. B 




LED READOUTS 

Fig, A MAN 1 Style with diffused segments for 

improved visability $2,75 

Fig. B MAN-1 Style $2,75 

Giant 0.6 in. LED similar to 

Fig. B $3.95 

Single LED lamp, red or clear, please specify. 

$.35 each, 3 for $1.00 
IC SPECIALS 

Stereo Amp. 2 watt per channel dual in-line 

package w/data $2.00 

Clack Chip ■ National 5314 12/24 hr 4 or 6 

digit 24 pin pkg w/data $12.95 

22 Pin PC card socket CU56 spacing $ .50 

WE Touch Tone Pad 12 button new $19.50 

5 MHz crystal miniature size w/wire leads ^ 

$2.50 



IC SOCKETS 




14 pin solder $.50 


wire wrap $-55 


16 pin solder $.55 


wire wrap $.60 


24 pin wire wrap 


$1.20 


28 pin wire wrap 


$1.30 


BUY TO & DEDUCT 10% 



THUMBWHEEL SWITCHES 

STANDARD SIZE - 0.5 x 2.125 x 1.78 
10 position decimal $3.00 

10 position BCD & compl.$4,00 
End Plates (per pair) $1.45 

MINIATURE SIZE - 0,312 x 1.3 x 1.3 
10 position decimal $2.50 

10- position BCD & eompL$3.75 
End Plates (per pair) $1.00 

Divider plates $1.25 



$5 Minimum Order. Visit us when in SL Louis. 
Please include sufficient postage. 



portable or mobile a tat ion. The original station li- 
cense shall be available for inspection by any author- 
ized Government official at all times while the station 
is being operated and at other times upon request 
made by an authorized represent a tire of the Commis- 
sion, except when such license has been filed with 
application for modification or renewal thereof, or has 
been mutilated, lost, or destroyed, and request has 
been made for- a duplicate license in accordance with 
| 97,57. 

§97*87 Station identification. 

(a) An amateur station shall be Identified by the 
transmission of its call sign at the beginning and end 
of each single transmission or exchange of transmis- 
sions and at intervals not to exceed 10 minutes during 
any single transmission or exchange of transmissions 
of more than tO minutes duration. Additionally, at the 
end of an exchange of telegraphy (other than tele- 
printer) or telephony transmissions between amateur 
stations, the call sign (or the generally accepted net- 
work identifier) shall be given for the station, or for 
at least one of the group of stations, with which com- 
munication was established, 

(h) When an amateur station is operated as a porta- 
ble or mobile station, the operator shall give the follow- 
ing additional identification at the end of each single 
transmission or exchange of transmissions: 

(1) When identifying by telegraphy, immediately 
after the call sign, transmit the fraction-bar I>N fol- 
lowed by the number of the call sign area in which the 
station is being operated, 

(2) When identifying by telephony, immediately 
after the call sign, transmit the word "portable" or 
"mobile", as appropriate, followed by the number of 
the call sign area in which the station is being operated. 

(c) When an amateur station is operated outside of 
the 10 call sign areas prescribed in § 97.51(b) and out- 
side of the jurisdiction of a foreign government, the 
operator shall give the following additional identifica- 
tion at the end of each single transmission or exchange 
of transmissions : 

(1> When identifying hj telegraphy, imm edia tely 
after the call sign, transmit the fraction-bar 1>N fol- 
lowed by the designator R 1, R 2, or R 3, to show the 
region {as defined by the International Radio Regula- 
tions, Geneva, 1959) In which the station is being 
operated* 

(2) When identifying by telephone,, immediately 
after the call sign, transmit the word * 'mobile" followed 
by the designator Region 1, Region 2; or Region 3, to 
show the region (as defined by the International Radio 
Regulations, Geneva, 1959) in which the station is 
being operated. 

(d) Under conditions when the control operator is 
other than the station licensee, the station identifica- 
tion shall be the assigned call sign for that station,. 
However, when a station is operated within the privi- 
leges of the operator's class of license but which exceeds 
those of the station licensee, station identification shall 
be made by following the station call sign with the 
operator's primary station call sign (i.e. WN4XYZ/ 
W4XX), 

(e) A repeater station shall be identified by radio* 
telephony or by radio telegraphy when in service at In- 
tervals not to exceed 5 minutes at a level of modulation 

Hudicieut to he intelligible -through the repeated trans- 
DiiHHinn. 

(f) A control station must he identified by its as- 
signed station call sign unlesn its emissions contain 
the call sign identification of the remotely controlled 
station. 



78 



73 MAGAZINE 



(ff> An nrjxiliary link sfniion mtist lie idf-ntififd by 
Ita DUHijfiiM] station rati tfjsn niiJrstf it.n emissions con- 
tain tin* call sien of its aH*oci:iti*d Htatinn. 

(h) The identification re<jrtirpd by para graphs (ah 
(b), (c), (d), (e>, (f) f and (%) of this m-tlon ftball 
be (riven on each frequency lielnc utilized for trana- 
mission nnd shall be transmitted either hy telegraphy 
u*tm? the International Morse eode t or by telephony, 
using tho EncIiMh Uinguage. If by an automatic derire 
only used for identification by telegraphy, the code 
npeed Jilmll not exceed 20 word* p**r minute. The use 
of a national or internationally recognized standard 
phonetic alphabet as an aid for correct telephone iden- 
tification Is encouraged- 

[S97,S7{<£) amended' end rede*, an (h) and new (d) t 
(e) t (/), and iff) added eff: 10-f7-72; FI(7£M] 

§97*89 Points of communications. 

(ft) Amnteor stations may communicate with: 

(1) Other amateur stations, excepting those pro* 
hlblted by Apj>endix 2, 

(2) Stations In other services licensed by the Com- 
mission and with lL3 f Government .stations for civil 
defense imr|*nses in accordance with Subpart F of this 
part, in emergencies and, on a tem|iornry bnuls, for test 
purposes. 

(3) Any station which ia authorized by the Commis- 
sion to communicate with amateur stations* 

(b) Amateur stations may be used for transmitting 
signal*, or communications, or energy, to receiving ap- 
paratus for the measurement of emissions, temporary 
observation of transmission phenomena, radio control 
of remote objects, and similar experimental purposes 
and for the purposes set forth In | 07.9L 

(c) Notwithstanding the provisions of paragraph 
(a), no more than two repeater stations may operate 
in tandem, i.e., one repeating the transmissions of the 
other, excepting emergency operations provided for in 
107,107 or brief periods to conduct emergency pre- 
paredness testa. 

(d) Control stations and auxiliary link stations may 
not be used to communicate with any other station than 
those shown in the system network diagram. 

[|£7.83 amended eff. 10-17-72: F/(72)-/] 

897.91 One-way communications. 

In addition to the experimental one-way transmis- 
sion permitted by § 07-8$, the following kinds of one- 
way communications, addressed to amateur stations, 
are authorised and will not be construed as broadcast- 
ing: (a) Emergency communications, including bona- 

i\*U* emergency drill practice transmissions; (b) In- 
formation bulletins consisting .solely of subject matter 
having direct interest to the amateur radio service 
as such ; (c) Round-table discussions or net-type op- 
erations where more than two amateur stations are 
in communication, each station taking a turn at trans- 
mitting to other station (e) of the group: and (d) 
Code practice transmissions intended for persons 
learning or improving proficiency in the International 
Morse Code, 

§ 97,93 Modulation of carrier, 

Except for brief tests or adjust incuts, an amateur 
radiotelephone station Nhall not emit a carrier wave 
ort frequencies below 51 megahertz unless modulated 
for the purpose of communication. Biugte audiofre- 
quency tones may be transmitted for test purposes of 
short duration for the development and perfection of 
amateur radio telephone equipment. 

(Continued next month.) 



m m 



At Last . 



Repeater Sophistication 
Is HERE 

Now at a realistic price you can have 
"Touch-Tone" command functions, 
autopatch, and control. It's the Signal 
Systems Decoder. 



MODEL TTD-1 

12/16 BUTTON DECODER 




Wired: 



Board $10.00 

Kit: 12 button S77 .00 

16 button S88.00 
12 button $85.00 
16 Button $98.00 

THE IDENTIFIER 

TO END ALL IDENTIFIERS 

ROM 2 Repeater-Identifier (CW-RTTY) 




Board 

Kit 

Wired 



8.00 Option I 
25.00 $30.00 
29.00 $35.00 



Here is the greatest buy on an identifi- 
er you'll ever find. 

Look for product review write-ups on 
these and other exciting new products 
from . . . 



mnntftr charge 



BiiNhAM t 'f?h 



'Sjb*, *,* , 






SIGNAL SYSTEMS 

2650 Durango Dr. 
Colorado Springs, 
CO 80910 

Phone toll free 800-525-5890 



OCTOBER 1973 



79 



IF YOU REALLY WANT THE BEST, 

YOUU JUST HAVE TO ACCEPT THE FACT 

THAT ITS GOING TO COST YOU A LITTLE LESS 



It's the little things that 
make a GTX the value it is: 

• Operation over the entire 2-meter band 
(including MARS and CAP frequencies) 
without tuning 

• No automatic shutdown on SWR bridge. 
Operate with mismatched antenna with- 
out damage, due to balanced emitter out- 
put transistors 

• Lowest AM detection level of any com- 
parable unit (including many commercial 
rigs) 

• Power: the GTX-2 and GTX-200 boast 
30 watts nom. output 



* . r 



Lightweight: manufactured to aviation 
industry standards 

High-sensitivity receiver pre-amp in- 
cluded as standard (GTX-2 and GTX- 
200) 

l A " phone jack included as standard 
(GTX-2 and GTX-200) 





GTX-200 



$269.95* 



(30 watts output power, 
nom., up to 100 channel 
combinations) 




GTX-2 



$259. 



95* 



(30 watts output power, 
nom., accommodates 10 
channels) 




GTX-10 



$209. 



95 



(10 watts output power, 
nom.. accommodates 10 
channels) 

* Includes 146.94 MHz. 
Add'l. crystals $6.50 ea. 



Don't Let An Honest Price Scare You Away- 
See Your Amateur Dealer Today! 



General Aviation Electronics, Inc., 4141 Kingman Drive, Indianapolis, Indiana 46226 - Area 317 - 546-1 1 II 



80 



73 MAGAZINE 



SEW* 



$49.95 



1 -2 WATTS I N 

15 WATTS PLUS OUT 



SOLID STATE 
SWITCHING 



Wired and Tested 

• 12-14 VOLTS 
NEGATIVE GROUND 

• LESS THAN 1 DB 
LOSS ON RECEIVE 




PA-1501 H 



Only 2" x2%"x 6% 



r r 



Also available: 



$39.95 complete kit 



RX-50C 30-60 MHz receiver kit w/crystal filter $59.95 

RX-144/220A 2/220 receiver kit 59.95 

RX-144/220F 2/220 receiver kit w/ceramic filter 65.95 



69.95 
29.95 
29.95 
29.95 
49.95 



• RX-144/220C 2/220 receiver kit w/crystal filter 

• TX-144 1 watt exciter 

• TX-220 1 watt exciter 

• PA-144/220 15 watt amp less cabinet, connectors, and switching 

• PA-144/220 25 watt amp less cabinet, connectors, and switching 

• PA-8005H 90 watt amp 5 watts in wired/tested 159.95 

• PA-8020H 90 watt amp 25 watts in wired'/tested 129.95 

• PA-432 10 watt amp less cabinet, connectors, and switching .... 39.95 

• PS-12 12 amp regulated 12-15 volt power supply kit 59.95 

• PS-12W Wired/tested 69.95 

• PS-24 24 amp same as PS-1 2 less case 69.95 

• COR-1 COR with 3 second and 3 minute timers 19.95 

Write for data sheets on any above units. Add postage. NY state residents add sales tax. 




HF ENGINEERING 

- DIV. of BROWNIAN ELECT. CORP. - 

320 WATER ST. POB 1921 BINGHAMTON, NY 13902 607-723-9574 



WORLD'S LARGEST SELECTION OF 

NEW & USED TV CAMERAS & ASSOC. EQUIPMENT 








iS2SS£25^ZB5SESS55S5SSS9 

Broadcast & Closed Circuit TV 
Audio and Video Systems 



PRICE 
$1.00 



INDEX PAGE 142 



CATALOG # 

973 S 1 



$1,00 ppd USA— $2.00 Foreign, 
Free to requests on Company 
Letterhead. 



THE PENSON ELECTRONICS CORP. 

9AM - 4PM Monday thru Friday; otherwise hy appointment 

OFFICE: Longview St. Tel. Area Code 203/875-5198 

L: Post Office Box 85 




ROCKVILLE, CONN. 06066 USA 



82 



73 MAGAZINE 



ANOTHER SELECTRONIC SPECIAL 

The R648/ARR41 Receiver 

Can be best described as a mini version of the R390A class 
of receivers, having most of the key features of the R39Qs. 
The unit covers from kc to 24.999 Me in 24 one 
megacycle bands. It does not include the band covering 1 
Mc to 2 Mc As you might surmise, the rec. includes two 
Collins mechanical filters. Operation of the receiver is most 
pleasurable, especially when tuning sideband, fncidentafly, 
the crystal controlled calibrator delivers a tone every 100 
kc and is of frequency meter accuracy. The receiver 
contains a dynamotor designed to operate from 27.5 volts 
DC at about 4 to 5 amps. Since most of the dynamotors are 
free of hash, retaining it and operating the set from 24 to 
28 v, DC is not really a bad alternative. If you wish to 
power with A.C. supply requirements are 250 V @1GQ ma. 
and 28v for fiL These sets are in like new condition 
overhauled and checked out. Wt. 34 lbs. 

Price: $1 75.00 ea. 



Solid State 866A Direct Replacement 

Price: $5.95 ea. or 2/$10.00 



R508 VHP Rec. 118-148 MHz 



Price: $14.95 ea 



MODERN ALUMINUM BENCH RACK CABINET 

11Vi" H x 18" D x 19" W. 8" panel openings 
w/rubber feet and disappearing handle. 

LtBlue Price: $7.95 ea 



R.F, AMPLIFIERS 
TUNES 50 to 100 mhz - COMPACT ALL 
ALUM, CASE 12" x 15" x 6% ft WITH SK 600 
EIMAC SOCKET. 1 LARGE AIR VARIABLE 
CAP. - 2 SMALL AIR VARIABLE TRIM- 
MERS - TEFLON MOUNTED ROTARY IN- 
DUCTOR - GOOD FOR LINEAR AMPLI- 
FIER - CAN USE EITHER 4 CX150A or 4 
CX250- LESS TUBE, PRICE: . , > $14.95 ea. 
WITH 4 CX150A, PRICE: . . . . $19:95 ea. 



ADJUSTABLE PRINTED CARD BOX 

For R ack Mount 
5" to 7%" — 16 slides and socke.s includes 
30 double contact position edge connector type 

Price: $9.95 ea. 

Receiver type VHF-2RM 108-135 MHz crystal control 
Double Conversion AM with AVC noise limiter and 
squelch-tunable, 1 15 volts, 50-60 cycles. Price; $24.95. 



WINTRONIX MODEL 850 INDUCED WAVE FORM 

ANALYZER, This unit, in conjunction with your present 
oscilloscope, permits you to view wave forms in the range 
from audio thru MHz without any direct connection. The 
probe is simply placed over the tube in question and the 
wave form is displayed on the oscilloscope. It may also be 
used as a high gain amplifier to increase scope sensitivity. 
Excellent for TV, radio, amplifier, and transmitter repair 
and maintenance. Brand new, with probe. 
SHiPWT. 13 lbs. Price: $19.95 ea. 



MODULE TYPE POWER SUPPLY 
TRANSISTOR, REGULATED. 
115V - 60 cycle in +12 -12 -6V @ 3 amp 
output. Front Panel adj + or -10%. On-off 
switch, Fuses. Barrier strip output. 6" x 5" x 
7", Excellent Ccmd. 
Ship.Wt, 10# Pnce; $14.95 ea. 



DIGITAL READOUT SET 

Make your own counter, frequency meter, 
digitaJ voltmeter, readouts, etc. 
Kit includes 

6 nixies with 6 sockets 

1 transformer 

1 P/S board w/socket 

PRICE: , . $12.95, 2/S20.00 



B-7971 LARGE ALPHA 
NUMERIC READOUT 

With sockets & driver board. Can be hardwired 
to form unusual house address numbers. 2 
tubes, 2 sockets, mounted on one driver board. 
Save $3.00 

Price: 5/$ 5.00 



COMPUTER TYPE CAPACITORS 

40,000 @ 20V 

32,500 @ 25V 

55,000 @ 15V 

1 00,000 @ 8V 

50d each or 5 for $2.00 

40,000 @ 10V 
30,000 @ 10V 
PRICE: 3 for $1.00 

Receiver R-36/GR 225-400 MHz. Crystal Control Double 
conversion FM with squelch and noise limiter, 600 ohms 
output, 1 15-230 Volts, 50-60 cps. Price; $24.95 

Just arrived. PS for R648 fits into receivers. Price: $24.95 



Coaxial relays, single pole 
UHF.BNC, Type N. Specify. 



double throw, available in 
Price :$4. 95 each. 



LAMBDA POWER SUPPLIES, LT 2095, 0*32 V 2 amp. 
rack mount. Like New. 

Pnce:$34.95 each. 



Adapters BNC to SO-239. 



Price: 2/$ 1.00. 



VACUUM VARIABLES, UCS 300, 300 mmF, 10,000 V. 
Price: $19.95 each. 



SPECIAL 
ONE OF A KIND 



Sorenson Power Supplies 
MA 28 30, 28 V, 30 A 
ERA 0-36 V, 50 A 
ERA 0-36 V p 20 A 



Price: $125,00 
Price: $150.00 
Price: $100.00 



Transmitter, 110 W FM, 406-420 Mc. Rack mount, with 
power supply. 

Price: $150.00 



ALL PRICES ARE F.O.B. OUR WAREHOUSE, PHILADELPHIA, PA. ALL MERCHANDISE DE- 
SCRIBED ACCURATELY TO THE BEST OF OUR KNOWLEDGE. YOUR PURCHASE MONEY RE- 
FUNDED IF NOT SATISFIED. TERMS ARE CASH, MIN. ORDER $5.00. ALL MERCHANDISE 
SUBJECT TO PRIOR SALE. RFE - REMOVED FROM EQUIPMENT. 



1206 South Napa Street 

215-468 7891 



SEIECTBONICS 



Philadelphia, PA 19146 
215-468-4645 



OCTOBER 1973 



S3 



AKHBajl 







THE ULTIMATE 

POWER 
SUPPLIES 

• 60 A @ SLIGHTLY LESS THAN 12 Vdc 

• NOMINAL OUTPUT: 50 A at 12 Vdc 

• BUILT-IN VOLTAGE & CURRENT METERING 

• WILL RUN A MOBILE RIG& EVEN AN AMPLIFIER FROM 110 Vac 

WALLER ELECTRONICS 
TEST EQUIPMENT SALES 

P.O. Box 9913, Chevy Chase, Md. 2001 5 

Telephone 301-652-0996 

SHIPPED FREIGHT COLLECT 



84 



73 MAGAZINE 



EXCITING NEW PRODUCTS 




2-METER PREAMP 
20 dB Gain, 2.5 N.F., 12V 



j § 



dc, Size 1" x 1ft" x y a 
Diode protected MQSFBT, 
90-day guarantee. Sh. wt, 4 
oz, Major Components 
Separately Shield ad. 

Wired ; . . . .$12,50 




TONE ENCODER 

Eight pre-adjusted tones. 
Duration and Output ad- 
justable, PLL circuitry for 
extreme stability, Choice 
of continuous or tone 
burst operation* Tone 
burst operation requires no 
batteries. Easy to install. 
Includes three special 
single or dual tones, 

TE8 KKit $31.95 

Wired . . ., . .$39.95 




TOUCH-TONE DIALER 

The electronic touch-tone 
dialer for home and car. 
It's safer and more accu- 
rate to use than a pad. 
Memory includes Access 
Code plus five phone num- 
bers. Numbers easily up- 
dated. Built-in monitor. 
Complete PTT operation 
with transmitter hold. 
TTD^4K 
WIRED .$59.00 

Kit $49,00 







• * ££ 



* <c 



***K* 



Mi 



nutd'MrcH caamuE 



AUTO-PATCH CONSOLE 

This mobile or home con- 
sole includes all the fea- 
tures you need for com- 
plete auto -patch operation. 
A Touch-Tone Pad; an 
automatic dialer for send- 
ing one access code plus 
five Touch-Tone phone 
numbers; a single /dual tone 
burst encoder adjusted to 
your choice of frequency 
above 500 Hz, and a built- 
in motor. Complete PTT 
operation with one second 
transmit it* r hold* 
APC-4K Kit ....... $84.50 

APC-4A Wired $98.50 



TOUCH-TONE DECODER 

A highly reliable twelve 
digit decoder with input 
protection, and PLL cir- 
cuitry for extremely stable 
operation. Heavy duty out- 
put relays, small size, plug- 
in circuit board. All these 
major features at an UN- 
BEATABLE price. 
TTD-12KKU .,..$89.50 
TTD-1 2 Wired . . . $129.50 






OjiIA [■■mitlia* <M* 



1 


2 


L :i 


[4 


La] 


[e'l 




[a] 


Q 


* ' 


[0 


[*» J 



TOUCH 1 OWE MO 

TOUCH TONE PAD 

In less than 15 minutes 
you can convert your por- 
table transceiver to Touch- 
Tone ©Deration* 
TTP Assembled . . . $44.50 

TTP Kit $34.50 

PAD-PULSER 

Now you can also obtain 
pulsed operation from 
your Touch Tone Pad, 
Convert Touch-Tone fre- 
quencies to decimal pulses 
at 2805 Hertz with just a 
flip of the switch. Option 
can be added to TTP-2/K, 
TTD-4/K and APC-4/K. 

PP 12K Kit $22.95 

PP-12Wired $29.95 

5— year guarantees. Send for Catalog 




VHF FREQUENCY 
STANDARD- FMS 5 

Cal. receive and transmit 
crystals in 10 P 6, 2 and 1 \ 
meter FM bands. Markers 
for all FM channels. Check 
deviation. Precision 12 
MHz crystal. No unwanted 
markers. Osc, and output 
buffered. Sh. wt, 2 lbs, 
( Less Batteries) t . $44,50 
Kit . ««.****... $37.50 




REPEATER ID 
Highly stable oscillator for 
automatic timing, AC or 
DC operation. ROM pro 
vides for more than 25 
characters, more than 
necessary for DC "any 
call" RPT. AUX is auto- 
matically added to ID if 
desired when main power 
is lost. Toneburst opera 
tion available. 
ID-101K Kit ..... $49.95 

ID- 101 Wired/Tested 

$69.95 

ID-101R assembled in Vti* 
rack cabinet ,...$109.00 




TONE DECODER 
Versatile single/dual ton*. 
decoder. PLL circuitry for 
extreme stability. 1 amp 
output relay can be reset 
automatically or manually. 
Monitor position. Adjus 
Table sensitivity. Internal 
strap selects single or dual 
tone operation. 

TD-2K Kit $31.95 

TD-2 Wired $39.95 



-OF 




r 



master charge 

■ ■ i H ' ■ -i h * * * * ►■■ 



Data EngiriEErin g , inc. $554 portRoyai Road 



V 



Ravensworth Industrial Park, Springfield VA 22151 

Phone: 703-321-7171 



OCTOBER 1973 



85 



< \P\UTOK YSSORTMENTS 



ANTENNAS 



INTIGRATI.I) CIKCUITS 



RESISTORS 



v. 

s 



3 



* i 



/- 



s 



2 

O 

2 



HAVE 




COPY 



OF OUR NEW 

CATALOG YET ? 



> 

n 

t 

to 









* 

m 

^ 



en 

O 

3 






2 



IF NOT, WRITE OR CIRCLE 

READER SERVICE CARD 
FOR YOUR COPY NOW! 



ffJ 
> 



53 






as 
O 

B 



u 
< 




§ 



P.O. BOX 773 



3 



v. 



oub siatti $y%im% a mt 



~ 

^ 



COLUMBIA, MISSOURI 65201 % 






(CALL TOLL FREE) 800-325 -2981 



sAV'idsiu uai • sx.\:'jkiuossv hoxsis;ih • sunn nNiiNnw) acivaaa iysmi yinti 






86 



73 MAGAZINE 




ipi 



-:-:-:-:•:■ 



WWW: 
: ivx': 

#:S;¥&W 




«wss 



:£&: 

'■"■ J , .".'. , V.".', J . 



:■:■; 



SC 250 8 DIGIT COUNTER SEMI-KIT with built in prescaler, and p.s. good up 

to approximately 250 MHz. Fully assembled and tested board. 

Send for data . . , $1 65 

ST-5A BOARDS ONLY (same size as those in the ST-6) $ 5.25 

ST-5A KIT OF ELECTRONIC PARTS , $ 54.00 

ST-6 BOARDS ONLY {these are the 8 original by W6FFC) $ 18.00 

ST-6 KIT OF ELECTRONIC PARTS $128.50 

MOD. KIT FOR UPDATING THE ST-5 TO THE ST5A ..........$ 9.00 

AK-1 BOARD ONLY (same size as those in the ST-6) , . - $ 3.25 

AK-1 KIT OF ELECTRONIC PARTS ( Same size as *hose in the ST-6) $ 20.00 

PEMCO MODEL 50A FREQUENCY COUNTER Sfcivn-KIT . $125.00 

This is a fully assembled and tested board with built-in power supply, cabinet, etc. 

Write for details. 

You must supply the cabinet, A.C. cord, meter, switches, etc. on all kits except where noted 
otherwise. (All prices are postage paid - we pay shipping.) 

If you have been putting off building because of circuit board layout, you have no 
problems . . . . just send a schematic to PEMCO and we will design and build your circuit 
board to ytur specs using high quality G10-FR4 2 oz. copper and tin plated for long 
resistance to oxidation. 



. .:■;■: •'£ 




fig 

;■■■" 



:>j;. yy.'Vwi 



;-X'V.v." ■:■ 
W-j-y/.-y.-i' 

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¥8 



:■:■:■:■:■:-■*:■- 



. .v.(i. .-.•.■.- 



PEMCO ■ 



ELECTRONICS 
nc. MANUFACTURING 



» 



422 18th St., N.E., Salem, Ore. 97301, (503) 585-1641 



mm 



■zy*±w&-]r:$fti& 



!.> j v.:jwv.;v:v:v,:.viv,',;, :■:>:»:■ xc-Ux^t-. 



:■:■: :■:-:-. . . : •: o>1o:o - - ■■:-:■ :-x.v.%:-»7*7':o ■ 



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.,... : . : .;. : .;. r : ; ;^>j.r.:.v.:-:.:''. 



^>^>^5^5SSSS ^>:-:::'x^«i$:SJ: ^S:¥;S:";¥: : :c-x: : ' • ' :£:W*K£: ; ; ; - : ; . .' 



OCTOBER 1973 



87 






Modal 

THIDXX 



HYGAIH 

A TRULY 
SUPER 
BEAM 



SUPER THUNDERBIRD TRIBANDER. Ulti- 
mate in tribander performance. 6 elements. 
For 10, IS and 20 meters. Gain 8.7 dB. F/B 
ratio, 25 dB. Input, 1 kw am, 2 fcw PEP. 
Longest element, 31.1'; boom 24'; turning 
radius 20'. Requires CDR HAM-M rotator* 
(See p. 12). 
Modal THIDXX. 66 lbs „_ —™ 171*15 

TH3MK3. improved super 3-element beam, 
10-15*20 meters, U lbs, 14445 

TH3JR. 600 watts PEP, 3 el. beam, 10-15-20 
meters. Turn radius 14.3\ 21 lbs, ... 9J.95 

TH2MK3. Improved 2 -element beam. 10-15-20 
meters, Turn radius, 14,3\ 22 lbs, .._ if JS 



HY- 
QUAD 



VHF 



QUAD and VHF BEAMS 

3-BAND, 2-ELEMENT HY-QUAO. Complete, 
nothing else to buy! Extra strong. For ID, 15, 20 
meters- fain, 8.5 dB. F/B ratio, 25-35 dB 52 
ohms. Spreader length, 25^5", boom dta., 2"; 
turning radius, 13'6". 
Medil HY-QUAO. 42 lbs, ,..* 1«-W 

3 ELEMENT, i-METER BEAM. Maximum perform- 
ance, rugged. Gain, 10 dB, F/B ratio, 20*25 
dB. Input, 1 kW. 52 ohms. Longest element, 
^10"; boom, W\ turning radius. &. 
Medal 6 3 EL 7 lbs DISCONTINUED 

{-ELEMENT, S-METER BEAM. Gain, 12.7 dB; 
F/B ratio. 20-25 dB. Input 1 fcW. 52 ohms. 
Longest eL, 9*11"; boom, 12'; turn, radius, 1'. 
Model MB io lbs _™™™,„ _.. 2i.se 

1-ELEMENT, 2 METER BEAM. Gain, 9 dB. F/B 
ratio, 20 dB. Input, 1 kW. 52 ohms. Longest 
element. y6*; boom 3'; turn, radius, *', 
Model 23* 4 lbs. _ _„_ M9 

8-ELEMENT, 2-METER BEAM. Gain, 14.5 dB. 
F/B ratio, 25-30 dB. Input 1 kW. 52 ohms. 
Longest el.. 3'6"r boom, 14'; turn, radius, 7'6*. 




MOSLEY 



Clastic 
Baa mi 




Trap 

Master 



CLASSIC t-ELEMENT BEAM. For 10, 15, 20 meters. Extremely 
rugged and lightweight, Rust and corrosion proof! Maximum 
gain with increased bandwidth. Rated 1 kW AM/CW, 2 kW 
PEP on SSB, 52 ohms. Longest element, 2^3"; boom, 24 r ; 
turning radius 19'3", ' 

Model CL-36. (Needs HAM-M rotator), 72 lbs 188 . 10 

Medal CL*33. As above, but 3-elements, Longest element, 
27'; boom, 16'; turning radius 16'. S dB gain. 47 153.75 

TRAP-MASTER SERIES. Provides outstanding performance on 
10, 15, 20 meters. Exclusive Mosley trap design offers resonant 
frequency stability under all weather conditions. Traps are 
weather and dirt-proof, 

TA-31. elements, 1 kW AM/CW, 2 kW PEP on SSB. Longest 
el., 2^; boom, 24'; turning radius, 19'3". 73 lbs 18 5 . 10 

TA-33, 3-etements, 1 kW AM/CW, 2 kW PEP on SSB. Longest 
el., 28'; boom, 14'; turning radius, 15'6". 41 lbs 143.40 

rA*33Jfl. 300 watt version of above. Longest element 26 / 8"; 
boom, 12'; turning radius, 14'9". 28 lbs. -- 100.00 

TA-32. 2-elements t rated 1 kW. Longest element, 28'; boom, 
7'j turning radius, 14'G". 29 lbs, 103.00- 

TA-32JR. 300 watt version of above. Longest element 26'8"; 
boom, 6'; turning radius, 13'. 20 lbs. 73 . 15 



A50-5 




144-11 




CUSH-CRAFT 



6 METER BEAMS, Proven performance, rugged. Engineered 
for best pattern, high forward gain, good F/B ratio and 
broad frequency response. Brackets are heavy gauge alumi- 
num. Horizontal or vertical mount. 52 ohms. 

Model A50-5. 5*elements, longest element, 117"; boom, 12'; 
turning radius, 7'6". 12 lbs 29.50 

Model A5D-3. 3-elaments. longest element, 117"; boom, 6'; 
turning radius, 6'. 8 lbs 18.50 



2 METER BEAMS. High performance VHF beams. Light- 
weight, rugged and easy to install. Horizontal or vertical 
mount. Features 1 kW Reddi Match for 52 ohm feed with 
PL-259 fitting. All elements are spaced at .2 wavelength and 
tapered for improved bandwidth. 

Model A144-7, 7-elements, boom length, 98". Fwd. gain, 11 dB; 
F/B ratio, 26 dB, 4 lbs . '[3 * 95 

Model A144-11. 11-elements, boom length, 144". Fwd. gain, 13 
dB; F/B ratio, 2d dB. 5 lbs. 17 ,95 

ZIPPER PORTABLE BEAM. For 6 and 2 meters. Full size 
performance and sturdy, swing-out portability. Ideal for 
emergency stations, camping, vacationing, etc. Complete 
package folded is 4 x 4 x 50" and weighs only 4 lbs. Tuned 
Reddi Match for 52 ohms. Longest elements, 117"t boom, 
66"* Ready -to- use. 

Model A2MP. Shpg. wt, 5 lbs. „ „ 17.95 




NEW MOSLEY 

TR1-BAND QUAD 

Designed for top OX efficiency. 
For 10, 15, 20 meters. Aluminum 
spreaders are well insulated for 
greater strength, P re-drilled for 
easy assembly. Maximum forward 
giin, F/B ratio, 20 dB, Rated 1 
kW on AM. 52 ohms. Spreader 
length, 12'6"; element length, 17'; 
boom, 8'; turning radius, &'. 
Modal MCQ-3B. 40 lbs. .„„ 111.50 




CUSH-CRAFT HALF WAVE SQUALQ 

Full half- wave, horizontal I y-po la r- 
ized, omnidirectional 6-meter an- 
tenna. Use it on car top, on mast, 
or out the window, Direct 52 ohm 
Reddi Match feed. Only 30" 
square. Complete with rubber suc- 
tion cups and mast support. 
Model ASM. 5 lbs „ 15J5 

Model A3Q 2. For 2 meters. 10" 
square. 3 lbs. _ _ 11 J5 




Elect r onix Sales 



23044 CRENSHAW BLVD.. TORRANCE, CALIF. 90505 
Phone (213) 5344456 or 5344402 

ALSO AMERICAN EXPRESS 
CLOSED SUNDAYS & MONDAYS 




88 



73 MAGAZINE 



CHARGE IT 
ON 



master charge 

THE INTEHBANK CARD 




CALL 




TRADE 




CHARGE IT 
ON 



BankAmericard 



we$mte^e&& 



CALL 




TRADE 



NEW 



CALL 
Bill Du Bord, W0KF 



USED 



(9 A.M.— 5 P.M. Central, daily except Sunday) 

FOR 
A SQUARE DEAL 








ON 

DRAKE 

TEMPO/ONE 

HALLICRAFTERS 

CLEGG 

STANDARD 








YAESU 

SWAN 

COLLINS 

KENWOOD 

REGENCY 



We carry all major brands and a large 
stock of used reconditioned equipment 

Write for used list 

HAM RADIO CENTER INC. 



8342 OLIVE BL. 



ST. LOUIS, MO 63132 



OCTOBER 1973 



89 






uiuvpuu 



Numttron 5V 7-Segment 
Siimline or Regular $2.50 ea. 



ZM 1000 Neon $1-75 

GE Y4075 25V Miniature 

$1 75 

GE Y 1938 24V Standard 

$1/75 

RAY CK 1905 Standard 

$1,75 

MAN-3 1.7V Miniature 
$3,50 m. 10/$30 

GIANT ALPHA NUMERIC 



OIL CAPS 16 MFD 5000 VOLT 
Rare find. $9.00 each 3 $25.00 



B7971 



$1.00 



NOISE ACTUATED SWITCH $1.35 
Solid stale notse actuated switch fully wired, 
includes mike pick-up, amplifier, SCR switch 
Actuates by noise or whistle. Useful for burglar 
alarms, lamp lighter, etc, 15 ft range, 



LIGHT EMITTING DIODES 3/S1.00 
Ruby red, gold plated leads. With mercury celt 
for instant testing. 



H.H, SCOTT MULTIPLEX 
Solid state brand new multiplex module w/ 
schematic. Possibility of conversion of various 
mono seis to stereo. $3.00 each 1 for $25 00 



Alpha-numenc keyboards. Excellent to new in condition. Styles may vary shghtly 
from picture. Two models available, one with ASCI I encoder in base $55.00 postpaid 
in the U.S. Keyboard with no encoder in base $35.00 postpaid in U.S. 



KEY BOARDS 
$35.00 & $55.00 




RCA MEMORY STACK 32x32x9 

3rd generation, ultra compact. Measures 1x4 
1/4x7. Brand new. $50.00 3 for $125.00 



CORE STACK 

Late model memory stacks, unused, 

I <\. A -J ************* *• * f « *J} O^ O -. \J \J 

2Kx9 50.00 

8K 4 bit Y plane . 40,00 

16K 4 bit Y-plane 60.00 

147K stack . . , . . 100,00 



HflMI 



AM-FIVI RADIO $20.00 

Fully built chassis by Delmonico with 
front panel, solid state- Also has stereo 
tape and stereo turntable inputs, 115 
VAC power. Brand new with schematics. 
$20,0(1 Made for console installation. 
Cost over $1 00.00. 



URC-11 WALKYTALKY 

243 MC 2 way radio, hand held, 
measures 3x4 inches. Used for 
survival in downed aircraft. May 
be converted for other frequen- 
cies. URC-11 $15 each or 3 for 
. $40.00 




12 VDC 3 AMP POWER KIT $5.00 

Just right for powering car tape deck, CB 
sets, car radio, etc. from regular house 
current. We furnish parts — transformer, 
silicon bridge, filtering caps, directions. 
Ail new parts, order #KT-3 at $5.00 ea or 
6 for $25.00. 




■i 



^rfesA^ 



7 SEGMENT LED 

Hobby craft due to being factory rejects. Most 
have a segment or decimal inoperative. Still a 
great "buy" for the experimenter. What an 
unusual tie clip you can make with pocket 
battery . , , demo displays, etc. In many appli- 
cations you don't need full 7 segments, $1.00 
each or $10 the dozen. 0.333 inches high 
character. 



GIANT 7 SEGMENT 

As above only this one is the giant display 
13/16 inches hgt of character. First time 
offered and as far as we know, offered nowhere 
else. This one is quite an attention getter. Also 
available in this giant display numeral "one" 
with "plus" and "minus" sign. Again, these are 
rejects. Giant display $1.50 each 12 for $15.00 



ostage extra on above. MESHN A PO Bx 62 E. Lynn Mass, 







COMPUTER KEYBOARD W/EN CODER %35 

Another shipment just received, Alpha-numerics 
keyboard excellent condition. Once again we 
expect an early sellout. Price of $35 includes 
prepaid shipment in the US and shipment made 
within 24 hours of receipt of order. 



POWER TRANSFORMER 

1 15ac/12V@3 amps . . . $2.50 

POWER AMP TRANSFORMER 

Brand new compact, regular 115 V 60 cycle 
input Output of 40 VCT at 4 amps plus 
another winding 6V at 2.5 amps. Fine business 
for Power Amps, Logic or Op Amp supply, 
$5-50 each or 5 for $25.00 



12VCT2AXFMR$t50 

Regular 115 volt 60 cycle input. 12 volt 
transformers are always in demand, these are 
brand new. $1.50 each or 10 for $12,00 



iC SPECIAL - ONE MONTH ONLY 

Our regular S1 5 IC board with appro*. 140 DIP 
ICs on them p with fdent sheet. For one month 
only we are pricing them at $6.50 per board to 
reduce our inventory. ^1C-S $6.50 Or 5 for $25 



COPPER CIRCUIT BOARD 

Brand new GE 2-sided glass epoxy G-10, the 
standard of the industry, bright and shiny new. 
6x12, Si. 00. 12 x 12, $1.50. 



AM-FM RADIO $5.50 

Due to the West Coast ship strike they came in 
too late for the customer. Now it's your 
bargain. Use it as is or build it into your own 
cabinet, desk, wail, etc. All built, ready to use, 
with AC supply. To make it portable all you do 
is power it with a couple of "D" cells. Fully 
assembled solid state chassis with AC power 
supply, less speakers. Covers full AM as weJI as 
FM broadcast. The price. . .an astounding 
meager $5.50 




PISTON CAPS 1-8 mmF 
3 for $1.00 



Unused Military surplus. For hi freq. work. List 
price over $3.00 each. We have 1 size only, 
1-8jUF. No hardware. 
^73-18 3 for $1.00 



60-SECOND TIMER 

A bonanza for the photo lab or any require- 
ment for a precision spring-wound timer, May 
be set at any interval 0—60 seconds. Contacts 
rated at 15 amps. Contacts close while running 
and open at end of time interval. Brand new. 

$1,50 each, 10 for $12 



455 KC IF ASSEMBLY 

Complete miniature 455kc I F. amp assembly. 
1.5 inches long, little over X A inch square. Ready 
to use w/schem. Sim to Miller 8902 2,50 



RF VACUUM 
SWITCH 

Made for the ART 13 
good for 100 watts RF, 
no doubt handles mufch 
more due to being urv 
denated for the mili- 
tary . . 1 #71-17 3/2.00 




■ -»' ' " k I 



7400 SERIES IC GRAB BAG 

Mix of 7400 series DIP, unmarked untested. 

Some schematics provided 10 for 1,00 

100 for 8.00 
1000 for 60.00 



I 




BATTERY ELIMINATOR- 
CHARGER 

Plugs into 115 volt 60 cycle and puts out 
approx. 12 volts DC 100 mils. Sufficient to 

power most any small transistor radio and also 
useful for charging small dry cells and small 
ni-cad cells, Fully built, ready to use. 
SI 00 each, 6 for $5.00 




GIANT LED83«I 

Price break at last on these giant LED with 
1,000,000 hours of life. Measure full 1/4 by 1/4 
inch. First time offered. 

RED S1.00 

GREEN 1.25 

SUPER BRIGHT coJiimated RED with para- 
bolic reflector, measures 3/16 diameter. A real 
hi-intensrty red visible over 100 ft, 

SUPER RED $1.25 



Postage extra on above. WIESHNA PO Bx 62 E. Lynn Mass. 01904 



OCTOBER 1973 



$ 



COMPUTER 
KEYBOARDS 

MANV NEW 

50 postpaid 




Just arrived, a superb batch of brand new keyboards still in original 
manufacturers cartons. Beautifully finished in pastel colors with contrasting 
colored keytops. Made for table operation with fully enclosed metal cabinet. 
Two encoder boards mounted inside the cabinet with connections terminat- 
ing on Spectra flat cable with plug. Key operation with bounceless magnet 
reed switch action. These computer keyboards were dumped as surplus by 
one of America's largest electronic companies and we were lucky enough to 
be on the receiving end. The price of $50 includes prepaid insured shipment 
in the US and shipment same day as order received. Orders out of the US 
require an extra $2.00. 



LOGIC 

POWER 

SUPPLY 

10 



$ 




With 400 of these power supplies on hand, we figure we'd better sell them 
cheap and get them off the floor or all will collapse with a great crashing roar 
and land in a heap in the cellar. 

These are from computer power supplies, used, good condition. Operate 
from standard house current. 4 output voltages .... MINUS 30 Vdc at 1 Amp, 
PLUS30Vdcat 1 / 2 Amp, PLUS 10 Vdc at 1 Amp, MINUS 10 Vdc at 1 / 2 Amp. 
Solid state construction with harmonic regulation on the transformer and 
transistor regulation on the 10 volt outputs. This is one helluva bargain and 
worth buying just to scrap for parts (if you're crazy enough to tear it apart). 
You've got 2 transistorized zener regulated plug-in boards with sockets and 
by changing the zener you can regulate from zero to 25 volts, 2 husky filter 
caps (18,000 (if at 35 volts), power transistors on heat sinks, a nice 
transformer, and misc. other parts. 

Ship. wgt. 37 lbs (you pay shipping) $10.00 each or 3/$25.00 







Postage extra on above. MESHNA P0 Bx 62 E. Lynn Mass. 01904 



92 



73 MAGAZINE 




PAY TV 
ASSEMBLY 

$15.00 



A "Super Value" for the gadgeteer. A complete Pay TV installation made for ZENITH 
and all in original packing (3 cartons — wgt 36 lbs) and all unused. Operates on regular 
115 volt 60 cycle power. A wealth of parts, easily removed due to long leads on 
components, most over one inch long. The 3 units consist of Translator, Adapter, 
Decoder. Transistors, tubes, solid state bridge power supply, geared clock motor, 35mm 
geared transport, time recorder, solenoid, relays, hundreds of small parts such as resistors, 
caps, etc. Our estimate as to cost to Zenith, approx $1,000 per set. Schematics with each 
purchase. One set of 3 units $15.00 wgt of 36 lbs. Special . , . 3 sets S35 wgt of 106 lbs. 
All unused, original boxed. 






COOLING FAN L 
BARRAGE 

$12.00 

For the photo enthusiast, electronic industry, people cooler; etc. Brand new assembly 
made by HOWARD Industries, 3 fans per panel, 1 15 volt 60 cycle. Each fan good for 100 
cfm and have blade guards both sides of each fan. To reverse flow of air, mount panel 
backwards. All brand new, ready to use. Silver gray panel finish. Standard 19 inch panel, 
5 1/4 inches high. Si 2 per panel of 3 fans or 2 panels of 6 fans for only S20. Ship wgt 7 
lbs per panel. 

AM-FM STEREO RADIO $18.00 AS IS 

THESE ARE FACTORY REJECTS TAKEN OFF THE LINE FOR REWORKING BUT 
THEN THE FACTORY CLOSED. We have UNUSED Solid State AM-FM radios with 
built in AC supply, extra outlets for tape, mike, or turntable. We furnish the schematic. 
These units made for console installation. Each with minor defects but we can furnish 
most any part found defective. 



Postage extra on above MESHNA P0 Bx 62 E. Lynn Mass. 01904 



yffesfm^ 



OCTOBER 1973 






Semiconductor Supermart 

• MOTOROLA • RCA • FAIRCHILD • NATIONAL • HEP • PLESSEY 



POPULAR IC*s 

MC1550 Motorola RF amp SI. 80 

CA302O RCA Y, W audio $3.07 

CA3020A RCA 1 audio S3.92 

CA3028A RCA RF amp $1.77 

UAJUU1 nUA, ■*■•••«**.*■ IjiO.OO 

MC1306P Motorola f /? W audio $1,10 

MC1350P High gain RF amp/1 F amp _$1.15 

MC1357P FM IF amp Quadrature del . $2.25 

MC1496 Hard to find Bai. Mod. ..... $3.25 

MFC9020 Motorola 2 -Watt audio . $2.50 

MFC4010 Multi-purpose wide band amp $1.25 

MFC8040 Low noise preamp ..«....« $1.50 

MC1303P Dual Stereo preamp $2.75 

MC1304P FM multiplexer stereo demod$4.95 

FETs 

MPF102 JFET , ., $.60 

MPF105/2N5459 JFET $.96 

MPF107/2N5486 JFET VHF/UHF. . $1.26 

MPF121 Lowcost dual gate VHF RF , . $.85 

MFE3007 Dual-gate $1.98 

40673 Dual-gate .- . $1.75 

3N140 Dual-gate $1.95 

3N141 Dual-gate . . . , , , $1.85 

NEW FAIRCHILD ECL 
HIGH SPEED DIGITAL IC'S 

9258 Dual J D" FF toggles beyond 160 MHZ 
....._... . . . . . $4.65 

9582 Mufti-function gate & amplifier . . . $3.15 
95H30 300 MHz decade counter ..... $16,00 
A 95 H 90 & 9582 makes an excellent prescaler 
to extend tow frequency counters to VHF — or 
use two 9528s for a 1 60 MHz prescaler* 



SIGNETiCS PHASE LOCK LOOP 
NE561B Phase Lock Loop «$4,75 

IME562B Phase Lock Loop >.«.,♦,*..♦. $4.75 

N5111A FM/IF Demodulator $1.50 

NE566V Function Generator .$4.75 

NE567V Tone Decoder . , , .$4.75 

TTL BARGAINS 

7400 . . . . . $.28 

7404 * * * $.30 

r " 1 *J ■ i • ■ • • ■ ■ • ■ - ■ • ■ <■*■■ ■■• . •* i» ■-••■■*P.vU 
f*Tj£.\J . »>•■•.•** + « »•**•»«■ ► ■ « . - .,.■». *J),0 U 

7446/7447 - $1.50 

f*4-/0 »*«•*« ....... **■.**« ''■'■''■'■ V I .UU 

7490 $1.00 

74192 $2.00 



NATIONAL CLOCK CHIP 



$12.50 



Set of circuit boards to build 
a digital clock $5.00 



CORES AND BEADS 



KW Balun kit only . 
T68 2 3 cores . 
T50-2 3 cores . 
T50-6 3 cores , 
T50-10 3 cores 
T 44-10 Scores 



. , i . 



• # » . ■ 



. . $2.00 
. . $3.50 
$1.00 
.$1.00 
.$1.00 
$1.00 
.$1.00 



BEAD SPECIAL 

Ferrite Beads 1 doz. 



$1.00 




INTRODUCING \p^DEVICES 
NEW LOW PRICES 

LA301 8 {Replaces CA3018 $1.60 

L A3046 ( Replaces CA3046) 1 .60 

LS370 (Replaces LM370) 4.00 

LS1 496 (Improved MC1496) 2.00 

LS3028A (Replaces CA3028) 1 .60 
LP1000 (A new fun-type device to make 

LED flashers, audio osc, timer etc.) 1 ,60 

LP2000 Microtransmitter 16.00 



THINKING 



R-4C 




DRAKE 




TR-4C 



T-4XC 



Check us out 



TR-22 



1 



NOW OPEN FOR LOCAL SHOPPING 
STOP BY AND CHEW THE RAG 

1110 N. Scottsdale Road 
Hayden Plaza East 

Please add 35tf for shipping 

Circuit Specialists 

Box 3047, Scottsdale, AZ 85257 

FACTORY AUTHORIZED DISTRIBUTOR FOR 

Motorola HEP - Circuit-Stick - Plessey 
All devices are first quality and are 
fully guaranteed. 



94 



73 MAGAZINE 





GAM has what your 

repeater needs 




8.2 dB GAIN OVER ISOTROPIC 




Vertical Radiation Pattern 



TG5-S 




— — — Dipole 
• **• Isotropic 



Horizontal Radiation Pattern 

— TG5-S 
———Dipole 

-•••Isotropic 



(ON FILE WITH FCC) 

MODEL TG5-S 

LIST PRICE 




$104 50 

Weight 3*4 lbs- 



Offset Side Mount Radiation Pattern 
Reference: Dipole 




Electronics 



191 VARNEY STREET 
MANCHESTER NH 03102 
TEL. (603) 627 1010 





OCTOBER 1973 



$70 





BOX 2673, OAKLAND AIRPORT, CA 94614 
555 Timers $1.10 ea 

Rfifi Rm 7 QR pa 

LED 7 seg. readout, .3 char size sim to MAN I 2.95/10 @2.50 

Power Supply, 5V 2.5 A & 28 V 1 A RO Type 602-28B 19.50 

BRAND NEW Flat Packs in carriers T! 7300/7400. Excellent 

assortment includes gates, flipflops 14.50 per 100. 

Digital Flat Packs U-Test-M Factory refect 4.95 per 100 

Small Memory Core Planes 3 types for experimental use . . .10.00 for 3 

Small ROTRON SPRITE (muffin) fan 30 CFM 5.95 

Red LEDs, excellent assortment 2.95 for 12 

Zener Diodes U-Test-M assorted 2.95 for 100 

1000 Assorted Resistors, Capacitors, Diodes including over 100 TTL 

DTL & Linear ICs on PC boards 10.00 

5V Digital Logic Supply Parts Kit with schematic easy to hook up! 
Includes line filter, transformer rectifiers filter & bypass caps 3 terminal 

regulator 5.50 

12V 8A REGULATED power supply parts kit. Ideal for powering 
FM rigs. Everything except the chassis 12.95 

ICs, most TTL & LINEAR in stock - Send Stamp for FREE Catalog 



CMOS 

74C00 

74C02 

74C04 

74C10 

74C20 

74C73 

74C74 

74C76 

74C107 

74C151 

74C160 

74C161 

74C162 

74C163 

74C195 



DIGITAL 

.70 

.70 

.95 

.70 

.70 
1.65 
1.50 
1.65 
1.65 
3.00 
3.25 
3.25 
3.25 
3.25 
3.50 



CD4001 
CD4002 
CD4009 
CD4010 
CD4011 
CD4012 
CD4013 
CD4016 
CD4019 
CD4023 
CD4025 
CD4035 



.70 

.70 

1.00 

1.00 

.70 

.70 

1.50 

1.50 

1.40 

.70 

.70 

3.00 



LINEAR 

LM370 

LM371 

LM372 

LM374 

LM380 

741T 
CA 3028 
CA3065 
CA 3086 



1.25 

1.25 Replaces HEP 590 

1.25 

2.00 

1.75 

.45 

.75 

.75 

.45 



Buy 10 ICs - 10% discount 
Buy 100 ICs - 20% discount 
All ICs tested and guaranteed 



LINEAR VOLTAGE REGS 

LM 309K 5V 1 A REG 2.00 

LM 320K NEG Reg available in 5V 12V & 15V 2.25 

LM 340K POS Reg available in 6V 12V & 15V 2.25 

LM 723 Adjustable precision reg 1 .00 

TRANSISTOR GRAB BAG mixed NPN PNP 1 00 for 2.95 

ALL ITEMS IN STOCK and will be shipped within 24 hours of receipt of order! 

Include 504 postage and handling on orders under $10.00, all others postpaid. 
Sorry, NO C. O.D. 's. CA LIFORNIA RESIDENTS ADD 6% sales tax. 



96 



73 MAGAZINE 





V 4 



-$ 






FM27B 
$479.00 



£ 



i 1 
I * * 

'Jh. ' 
■I 


~ 


^ 


''. 


" 


■ 


1 


_ 


| Att>B 1 


f X j 






W( 




■' 


*-jj^g 



Wfe sfoc/r Hy-Gain, 
Antenna Specialists, Hustler, 
-* CushCraft and Shakespeare. 

4// 2 meter xtals 

in stock . . . Bo mar 3.95 







L r* :jirv.J ' ■■<*' -iff '* 



FM-21 220 MC $299.00 



^*^ 
&> 



*? 















We also stock VHF 
and UHF amplifiers 
TPL, Dy-Comm, Standard 



,: 



£ 



£$ with each Regency rig you purchase. . . you receive 4 FREE CRYSTALS of your choice! 




^o„ 

* 7 



t 




HR 2B NEW 

1 2 ch xmt-rcv 
1 5W min 

$229.00 



HR-220 NEW 

1 2 ch 20W 220 MC 

$239.00 

[i 
% 

$ 



AR-2 

80W 2 meter amp. 

$100.00 

EC 175 

175 MC counter 

$400.00 



HR-6 

6 meter 25W 

$239.00 

HR-212 

1 2 ch 20 watt 

$259.00 



s. 

FN 














*.■ 



>*1 



Standard 

Communications 

146A 

2 meter walkie 

$289.00 

SR815TH 
25W 1 2 ch 
$589.00 ' 



*V*i£ 









sr*: 



at 



|SB 




SB 450 

12 ch 10W 
450 MC 

$399.00 



SB-144 

12ch 10 W 

$259.00 



9 

^ * 



^J 









826MA SCARPT-1A 

12 ch 10 watts 2 meter RPT 

$398.00 $690.00 



SRC14 

24 ch 10 watt 

base unit 

$598.00 



SEND FOR OUR CATALOG WITH SPECIAL PRICES 



► ■TV 

to 

la 



i ■ 



i 



U 



491 Riverside, Medford, Mass. 02155 

(617-396-5550) 



OCTOB£R 1973 



97 



?& E CALCULATOR kmSS*o 

Attractively designed! 1 ! Excellent craftsmanship 

Case and keyboard (designed as one unitl 

Cabinet is made oT high- impact plastic 

beige color with black bezel and 

amber window. Keyboard consists 

of a J position slide switch and 

25 keys, 5 of which are used for 

memory function. 20 keys gray, 5 

keys orange* All keys mounted on 

one printed circuit board.....*. 




11" wide X 10. S M X 2. 9" high 



This nodular unit Is well 
suited for our calculator 
chips . Ideal for the CT5QQ5 

Case and keyboard complete 

only S29.95 



3 CHIP CALCULATOR 

This calculator set provides all of 
the electronics for an eight digit, 
floating point calculator with left 
hand entry*. Keyboard, display .clock 
generator, and display driver is all 
that need be added to make a calcu- 
that will add, subtract, multiply, 
and divide. Overflow and negative 
signals are also provided. Complete 
instructions to build a calculator 
included , . . 

Chips and data — — — S7«95 

Data only --1,00 

(refundable) 




ICT5005 CALCULATOR 



This calculator chip has a full four 
function memory, which is controlled 
by four keys, +M (adds entry into me- 
mory) , -M {subtract entry from memo- 
ry) , CM (clear memory- -without clear- 
ing rest of registers) t RM (read rae- 
ory or use as entry) , 




12 digit display and calc . 

fixed decimal at 0,1,2,3,4, or 5 

leading zero suppression 

seven segment multiplexed output 

true credit sign display 

single 29 pin chip 

Chip and data >---- $14-95 

Data only {refundable) — — — 1.00 



5001 CALCULATOR 

40 pin calculator chip will add, sub* 
tract, multiply* and divide. 12 digit! 
display and calculate. Chain calcula- 
tions* True credit balance sign out- 
put* Automatic overflow indication. 
Fixed decimal point at 0, 2, 3, or 4 
Leading zero suppression. Complete 
data supplied with chip. 

Chip and data, only S9.95 
Data only (refundable) 51, 00 



All 1C " s are new and Fully tested 
leads are plated with gold or solder 
Orders for $5 or more will be ship- 
ped prepaid. Add 35C for handling and 
postage for smaller orders, residents 
in California add sales tax. IC or- 
ders are shipped within two workdays 
of receipt of order-kits are shipped 
withen ten days of receipt of order. 
$10.00 minimum on C.0.D;*s (phone in) , 
f916) 96G21 Zip~95606 

P.O. Box J 
Carmichael 
Cal i forma 
GUARANTEE Oti ALL GOODS. . * 




r 



keyboard General 
Telephone 



Ten push buttons (0-9 
touch-tone^ encoding, 
programming devices* 
Easy for panel mount- 
ing. Size 



: 5X2WJ 



rciEIHQRV SALE!! 

256x1 BIT Random Access Memory 

Fully decoded TTL Compatible 

fnpot and output. No clock or 
refresh required. 

INTEL 1101 MOS 

16 pin DlP-full data a cc 
U per BIT— each *£,OD 

10 for$22«56 



7400 series DIP! 



7400 


S .35 


74H53 


*50 


74HO0 


.50 


74S4 


.36 


7401 


. 35 


74L54 


.50 


74H01 


,50 


74L5S 


.50 


7403 


,33 


74*0 


.35 


7404 


.35 


74L71 


.30 


74L04 


,50 


7472 


,50 


74H04 


,50 


74L72 


,60 


7405 


.35 


7473 


.65 


74H05 


.50 


74L7 3 


,90 


74H0B 


.50 


7474 


,65 


7410 


.35 


74L74 


.90 


74L10 


.50 


74K74 


.go 


74H11 


.60 


7476 


.70 


7413 


1.75 


74L7A 


1. 00 


74 20 


.35 


7490 


,6S 


74L20 


,50 


7463 


1*30 


74H2Q 


.50 


74B6 


♦ 80 


74H22 


•BO 






7430 


.35 






74L30 


,50 


7491 


1*15 


7440 


-35 


7492 


1,15 


74H40 


.SO 


7493 


1.15 


7441 


1.60 


7495 


1.25 


7442 


1.30 


74L95 


2*00 


7446 


1*75 


74107 


*70 


7447 


1.75 


74121 


1.60 


7448 


1.15 


74123 


2,00 


7450 


.35 


74154 


2*50 


74H50 


.50 






7451 


.35 


74192 


2,50 


74L51 


.50 


74193 


1.50 


74HS1 


■50 


7419S 


1 .10 


7453 


.35 







. RECTIFIERS 


flil Varo Bridg 


H 


III/ VS447 


2A 


400V $ .90 


J*** VS647 2A 
35A Stud 


6oov - iao 

400V "* 1.10 


/ M&810 




50V 1A .10 


/ 1N4997 




50V 1A .10 


1 1N4001 




1A .10 


9 1N4002 




1A .11 


/ 1N4003 




1A .12 


/ 1N4004 




1A .13 


f 1S4DQ7 




1A .17 


£|j£CF 


Vs 




MB IR122 




100V8AKP -50 


Fj IR122 
/// 1R122 

iJJ IR122 




200V BAHP ,60 




300V 8AHP .80 




400V SANPl'OO 



LED's 



MV-50 red emitting lO-40ma^2V 5 for 
ft— 

MV5054^ red LED l5-l30mag2V S .30 

10 for 2.50 



$ .25 

1*00 





$ .30 
MV-109 visible red 5-70ma 2V 10 for 2.50 




GIANT "NIXIE" 

Comes complete with Socket and DD700 202 
Numeric Driver. Readability 1n high am- 
bient light... 200 footlanrberts bright- 
ness! I All DC operation. Long life with 
no loss of brightness. Compatible with 
conventional solid state circuitry. 




Only S2*25 



These were 
used in the 
New York 
Stock Ex- 
change 



HCfl £010 MUMJTRQN 

Popular digital display tube. 
This incandescent five volt, 
seven segment device provides 
a -6" high numeral which can 
be seen from a distance of 30 
feet* The tube has a standard 
nine pin base (solderable) and 
a left hand decimal point.... 



$5.00 each 



54.00 each for 5 or more 





til III 

Seven Segment #0-9 plus letters* 

Snaps in 14-pin DIP socket or 
He lex. Operates with XC voltage 
requirements ■ Long operating life 

$4.25 each 




MAN l* 



Seven segment*Q-9 plus letters* j 

Right hand decimal point. Snaps* 

in 14-pin DIP socket or Molex.^/^ 

IC voltage requirements* ideal ; ™" ■ 

for desk or pocket calculators!* 

< 



Each ...**.... s 3 * 00 
Ten or more. . $25*00 



red lens 



NAM a 



0*9 plus letters. Right hand 
decimal point. flat-Pack type 
case. Long operating life. IC 
voltage requirements. Ideal 
for pocket calculators 



1 1 1 1 1 



c*a en ......*.«^ * . u u 

Ten or more.. $20. 00 




red lens 





LINEARS 




HK531 


op amp TO-5 


$2.00 


NES60 


phase lock loop DIP 


J. 25 


NE561 


phase lock loop DIP 


3.25 


WE565 


phase lock loop TO-5 


3.25 


SE566 


function generator TO-5 


4.00 


KE567 


tone decoder TO-5 


4.00 


HE5556 


op amp DIP 


l.oo 


709 


popular op amp DIP 


.45 


710 


voltage comparator DIP 


.50 


711 


dual comparator DIP 


.40 


723 


precision voltage regulator DIP 


1.00 


747 


dual 741 op asp DIP 


1.00 


743 


op amp TQ-5 


1.00 


LH100 


positive DC regulator TO-5 


1.00 


LM302 


op amp voltage follower TO-5 


1.25 


LK1595 


4 quadrant multiplier 


52.00 


mill 


comparator TO— 5 


1.75 


LK380 


2W audio amp DIP 


1.75 


LN703 


RF-IF amp epoxy TO-5 


1.00 


U4309H 


5V-200ma power supply TO- 5 


1*00 


LM309K 


5V-1A power supply module TO-3 


2.00 



FREQUENCY SYNTHESIZERS 



*-v£ 



YOU'LL NEVER 

HAVE TO BUY 

CRYSTALS 

AGAIN! 



* 




>■ 






MODEL rST-1 40 

Price: $129.95 ppd. 
Tested, guaranteed and 
complete with mobile 
mounting bracket , tilt 
stand and transmitter 
matching kit. 

NOTE: NY State residents 
add sales tax, 

CHECK THE ADVANTAGES OF A VANGUARD SYNTHESIZER OVER OTHER BRANDS... 



(excluding 
transmitter 



* No microphonic*. Can be uied mobile over bumpy roads. 

• Reference frequency and spurious output down 70 dB 
harmonics of output frequency which are used in the 
anyvwy) 

* All output frequencies are generated directly from the VCO without the 
use of multipliers and are therefore free of sub-harmomcs. 

• Now available witn outputs in the 6. 8, 1? end 18 MHz bands 
(corresponding to 144 MM?, dial reading) for direct substitution of 
transmitting crystals. More output frequencies are being made available 
Gall us if you don't see what you need. 

* Entire frequency appears inline in clear digits. No guesswork or mental 
addition*. Thumbwheel switches provide fast, accurate selection of 1000 
channels in 10 KHz. steps from 140 00 to 149 99 MHz 

• 50 ohm output and impedance transformer kit allows use at any distance 
from transmitter. 



Maintains an accuracy of 0005% (5 parts per mi ll ion I over the entire <ange 
of 10" to +60 C with a precision temperature compensated crystal that 
requires no oven. Operates at & MHz, for easy checking with WWV end 
includes a zero trimmer for correcting long term aging drift 
Fast response time of only 3 milliseconds for a TO KHz. step chance in 
frequency and a remote control, gated output amplifier for push to talk 
operation. 
No hunting or fabe locks as with some other synthesizers 

Operates from 10 to 15 VDC, 3 precision regulators eliminate input 
voltage fluctuations. Can also be used on 110 volts AC with a vnaii 12 
vglt J>7 amp pernor supply. 

Smallest sue of any commercial synthesizer Only 1 3/B J ' high. 3-5/8" 
wide, 8" long. 

All IC'S are mounted rn high quality insulated sockets and aJI parts *re 
marked. 
Manufactured by VANGUARD LABS renowned lor qua lity s ince ! 9S?. 



NOTE: Our 45 MHz receive synthesizers are now in production. Call us for details. 
IMPORTANT: When ordering be sure to state the output frequency you want. 



PRE-AMPS 


CONVERTERS 


VHF FM RECEIVER 





VA NGUAKD 




HIGH GAIN • LOW NOISE 

35 dB power gain, 2.5—3.0 dB 
N F. at 150 MHz, 2 stage, R.F. 
protected, dual-gate MOS- 
FETS. Manual gain control 
and provision for AGC. 4-3:8" 
x 1-7/8" x 1*3/8" aluminum 
case with BNC receptacles and 
power switch. Available fac- 
tory tuned to the frequency of 
your choice from 5 MHz to 
350 MHz with approximately 
3% bandwidth, Up to 10% 
B W. available on special or- 
der. 
Model 201 price: 

5—200 MHz $24.95 

201—350 MHz $28.95 



HOW TO ORDER: 

AM the items o*> this pac^ are available only from 
Vanguard Labs, For receivers and converters, $tat£ 
model input arid output frequencies and band- 
width were applicable. Remit En full, including 
sales tax if vou reside in New York State, direct to 
Vanguard Labs, Prices include postage by regular 
parcel post. For air mail or specie' delivery include 
extra amount; excess will be refunded. Send 
money order or certified check for faster shipment. 



40 dB GAIN 2.6-3.0 N,F. 9 160 MH* 

2 RF sugei with transient protected 
du*)-f*te MOSFETS give thU convener 
the high i*in and Low notw you need fo* 
receiving very weak lUnal* The mixer 
stage ts alio a dual-gate MOSFET u it 
greatly reduces spurious mixing products 
— some by as much as lOO dB over that 
obtained with bipolar mixers A bipolar 
osc ilia tor using 3rd or 5th overtone 
plug-in crystals is followed by a har- 
monic bandpass filter, and where neces- 
sary an additional amplifier is used to 
assure the correct amount of drive to the 
mixer. Available in your choice of input 
frequencies from 5—350 MH/. and with 
any output you choose within this range. 
The usable bandwidth is appro* > 3% of 
the input frequency with a maximum of 
4 MH*, Wider band widths are available 
on special order. Although any frequen- 
cy combination is possible (including 
converting up) best results are ob tamed 
if you choose an output frequency not 
more than W3 or less than 1/20 of the 
input frequency. Enclosed in a 4-3/8" x 
3" x 1-1/4" aluminum case with BNC 
receptacles, power and antenna transfer 
switch. Thousands of our converters are 
now in use by satisfied customers, many 
of whom are government agencies and 
universities. 
Model 407 price: 

&— 200 MHz $49.95 

201—350 MHz i .:.->.., * $54.95 

Prices include 005% crystal. Additional 
crystals £5.95 each. 



1 1 CHANNELS • 1 35-250 MHz 

• 11 crystal-controlled chan- 
nels # Available in your choice 
of frequencies from 135 — 250 
MHz in any one segment from 
1—4 MHz wide* I. F. band* 
width (channel selectivity) 
available in your choice of 
±7.5 kHz or ±15 kHz. • 8-pole 
quartz filter and a 4-pole cera- 
mic filter gives more than 80 
dB rejection at 2X channel 
bandwidth • Frequency trim* 
mers for each crystal # . 2 to .3 
jJLvolt for 20 dB quieting • Dual- 
gate MOSFETS and integrat- 
ed circuits # Self-contained 
speaker and external speaker 

jack # Mobile mount and tilt 
stand # Anodized aluminum 
case. 6"x 7" x l-3/8'\ 
Model FMR-250-11 price: 

135—180 MHz $119.95 

181—250 MHz $129.95 

Price includes one .001% 
crystal. Additional crystals 
$6.95 each* 



VANGUARD LABS 



Call 21 2 468-2720 for fast C.O.D. shipment. 

136-23 JAMAICA AVE. H0LLIS, N.Y. 11423 






OCTOBER 1973 



For the most powerful antennas under the sun 





the 

2 Meter Fixed Station 



268 



Designed for the man who demands professional standards in 
2 meter equipment. REPEATER LINE fixed station antennas 
are the 2 meter HAM's dream come true. With everything you 
need for top fixed station performance... toughness, efficiency 
and the gain to gain access to distant repeaters with ease. 
Work many stations, fixed or mobile, without access to a 
repeater. 

The right antennas for the new FM transceivers... or any 2 
meter fixed station. 

REPEATER LINE Fixed Station Antennas 

Tough, high efficiency antennas with a long, low radiation. For 
the top signal and reception you want... and the top perfor- 
mance your transceiver's ready to deliver. 




267 



231 15 element high performance 
beam. 17.8 db gain. Coaxial balun. 
Beta Match. Unidirectional. Boom 
length 28'. VSWR 1.5:1 52 ohm 
feedpoint. Extra -strength heavy 
wall commercial aluminum tubing. 

267 Standard 1/4 wave ground 
plane. May be precision tuned to 
any discrete frequency between 
108 and 450 MHz. Takes maximum 
legal power. Accepts PL-259. Con- 
structed of heavy gauge seamless 
aluminum tubing. 



268 For repeater use. Special stacked 4 dipole configuration. 
9.5 db offset gain. 6.1 db omnidirectional gain. Heavy wall 
commercial type construction. 144 thru 174 MHz. 1.5:1 VSWR 
over 15 MHz bandwidth eliminates field tuning. Extreme band- 
width great for repeater use. Center fed for best low angle 
radiation. DC ground. Complete with plated steel mounting 
clamps. 



100 



73 MAGAZINE 



from 



hygal 



341 



Antennas with real PUNCH! 



340 3 element high perfor- 
mance beam. 9 db gain. Co- 
axial balun. Special VHF 
Beta Match configuration. 
Unidirectional pattern. 
VSWR 1 .5:1 . 52 ohm imped- 
ance. Heavy gauge alumi- 
num tubing and tough alumi- 
num rod construction. i j 349 

341 8 element high perror- 
mance beam. 14.5 db gain. 
Coaxial balun. VHF Beta 
Match. Unidirectional. Boom 
length 14'. VSWR 1.5:1. 52 
ohm feedpoint. Heavy gauge 
commercial type aluminum 
construction. 

338 Colinear ground plane. 3.4 db gain 
omnidirectionally. Vertically polarized. 
52 ohm match. Radiator of seamless 
aluminum tubing; radials of solid alumi- 
num rod. VSWR less than 1.5:1. All steel 
parts iridite treated. Accepts PL-259. 

362 SJ2S4 high performance all-driven 
stacked array. 4 vertically polarized di- 
poles. 6.2 omnidirectional gain. 52 ohm. 
May be mounted on mast or roof saddle. 
Unique phasing and matching harness 
for perfect parallel phase relationship. 
Center fed. Broad band response. DC 
ground. 

WRITE FOR DETAILS 

For top fixed station performance on 2 meters 

THE REPEATER LINE 

From 

HY-GAIN ELECTRONICS CORPORATION 



362 



338 



Dept. CK, 8601 Northeast Highway Six 
402/434-91 51 



Lincoln, NE 68507 
Telex 48-6424 



OCTOBER 1973 



101 



S & R Enterprises 

1344 E. Indian School Rd.-Phoenix, AZ 85014 

(602) 277-2712 

This Month's Specials 




^&rt^ 



MJE 340 

MJE3Q55 

MJE1093 

MJEUOO 

3U4913 

2N4910 

2N4912 

2N4399 

2N377I 

2N4B01 

2N37H 

2N3055 

3N1545 

2N3238 

2N1358A 

2N«05 

2SB473 




Motorola RF Transistors Sale 

(Unmarked) 
QlT Type 

2673 2N3866 3/1. 90 

384 2N5589 3/6,00 

12$ 2N559Q 3/9- 50 

48 2N5591 3/20. 00 

227 2N6Q80 3/6,00 

2S0 2N60S1 3/9. SO 

174 2M8082 3/16.00 

174 2N8083 3/24. 00 

260 2N6084 3/40. 00 

50 2N6166 3/50. 00 

Please do not mix ! 

^ — ^ . 

Motorola RF Transistors Stole 

(Marked) 
Qty Type 

3 2N1692 

3 2NL693 

1 2N2857 

2 2N28S7 
9 2N2947 
419 2N3925 
13 2N39S0 
1963 2N4072 
2 2N4Q73 
1361 2N5I09 
1 2N5I77 
1754 2NS179 
I 2N5583 
33 2N5590 

16 2N5643 

4 2 N 58 49 

MM 1622 
U 2N5862 

U 2N5942 

42 2N5591 

30 2N6Q64 

330 MMieaa/ 

2N6084 

U 2N6097 IS. 00 

1 2N6135 5.00 
40 2N6166 30, 00 

2 2N6266 40, 00 
% MM1500 2.00 
990 MM1607/ 2.00 

2N5842 

3 MM1620 
1 MM1661 

23 MM1669 
1000 MM8006 
1 MRF207 

4 MRF209 

17 MRF304 
30 2S6081 

24 2N60S2 

25 2N6083 



Motorola ICs, RTL, DTL, ECL, 
Some in limited quantity. 



in 



816 
827 

830 
832 

833 

836 

637 
839 
844 
845 
846 
848 
849 
851 
853 
855 
862 
880 
889 
930 
944 
945 
946 
BID 
K)14 
HU5 
1020 
1023 
1096 
1125 
1213 
1223 
1302 
1511 
1802 
1806 
1610 
1811 
2363 
3002 
3081 
4000 
4006 
6160 
8603 
9709 
9718 
9719 
9720 
14010 



LOO 
LOO 
2.00 
2.00 
3.00 
3.00 
3,00 
3.00 
2.00 
3.00 
2-00 
3,00 
2.00 
7.00 
2.00 
2.00 
LOO 
2,00 
LOO 
4.00 
4.00 
6.00 
4.00 
L00 
2.00 
2.00 
LOO 
L50 
2.00 
5,00 
3.00 
2,00 
LOO 
8.00 
.50 
-50 
.50 
.50 
5.00 
LOO 
3.00 
2.00 
2.00 
W.00 
3.00 
LOO 
LOO 
LOO 
LOO 
2.00 



linear ICs 
723 



Power Transistors FETs 



LOO 2N3O70 

LOO 2N3438 

L 00 2N3821 

2.00 2N4343 

LOO 2N4391 

. 85 2N4352 

LOO 2N4166 

LOO 2N5460 

LOO 2NS465 

LOO 2N5556 

LOO 3N140 

L 25 3N141 

LOO MFE10000 

2.00 MFE2O01 

2.00 MPF102 

L25 MPF120 
L25 




SCRs 
2N4443 
2N5061 
T140A2 



a> « p* « t* *2 ^ 



^ in iA u> tr> Q u> 

H q Oi f- in ij Uj 

aj -* . . . . *™ , 

! —* pa ■«• « cq -J v 



— i ui to r- 

c o o o 

r- fv to OT W to 

o+ n &, a, a* Pi 

U r; (^ [ti cj [xj 

X X S K X X 




ICC- 2 

ICC-3 

ICC- 50 

1CC-5I 

1CC-52 

ICC-53 

ICC-54 

ICC-55 

ICC- 56 

jCC-57 

ICC- 134 

ICC- 151 

ICC-154 

ICC- 156 

ICC-157 

ICC- 158 

ICC-162 

ICC- 170 



SI 
SI 
51 
SI 
SI 



RF 
RF 

RF 



V 



s$ 



& 



SI 
81 

SI 
31 
SI 



GE RF Transistor - PNP-7GG MK2-300 MW 
GE RF Transistor - PNP- 250 MHz-300 MW 
SI RF Transistor - NPN-250 MHz -400 MW 
Transistor - PNP-150 MHz-GOO MW 
Transistor - PNP-300 MHz-40G MW 
Transistor - NPN-200 MHz- 60 MW 
RF Transistor - NPN-30 MHz-310 MW 
RF Transistor - NPN-3O0 MHz- 310 MW 
SI UHF Oscillator - NPN-750 MHa-3iO MW 
SI RF Transistor - PNF-200 MHz-310 MW 
GE Diode (1N34A, 1N60, LN541, IN295, IN64) Substitute 
SI Power Rectifier-Stud- 50 PIV-15 Amps 
SI Rectifier- Axial Lead-50 PIV-1 Amp 
Rectifier- Axial Lead-200 PIV-1 Amp 
Rectifier- Axial Lead- 400 PIV-l Amp 
Rectifier- Axial Lead -600 PIV-1 Amp 
Rectifier- Axial Lead- 300 PIV-3 Amps 
Rectifier- Axial Uad-XXH) PIV-2. 5 Amps 
ICC t30 GE Power Transistor-PNP-to-3-5 Amps - 90 Watts 
1CC-231 GE Power Transistor- PNP -to -3 6- 15 Amps - 150 Watts 
1CC-292 GE Power TransLstor-PNP-to-3-7 Amps - 90 Watts 
ICC-238 GE General Purpose PWR Transistor - PNP-60V-3 A. 
ICC- 240 SI Power Transistor - NPN-300V-50O MA - 10 Watts 
ICC- 241 SI High Power Transistor - NPN-160 V 5 Amps-40 W, 
ICC- 242 SI Med, Power Translator- PNP-60V-3 Amps-6 Watts 
ICC- 243 SI Med. Power Transistor- NPN-80V-3 Amps-6 Watts 
ICC-245 SI Med. Power Transistor- NPN-60V-3 Amps-30 Watts 
ICC- 246 SI Med. Power Transistor- PNP-60V-3 Amps-30 Watts 
ICC-250 GE General Purpose Transistor -PNP- Med. Gain-200 MW 
ICC-251 GE General Purpose T ran Blstor- PHP- Med. Gain-200MW 
ICC-253 GE General Purpose Transistor- PNP -Med Galn-225MW 
ICC-254 GE General Purpose Transistor -PNP- Med Galn-225MW 
ICC-310 SI Unijunction Transistor - 300 MW 
ICC-631 GE General Purpose Audio Amplifier - PNP 
ICC-632 GE General Purpose Audio Amplifier - PNP 
ICC-633 GE General Purpose Audio Amplifier - PNP 
ICC-637 GE General Purpose RF-PNP 

GE General Purpose Drift- Held - PNP 
GE General Purpose Drift Field - PNP 
GE General Purpose Drift Flekt - PNP 
GE General Purpose RF and Audio Amplifier - NPN 
SI General Purpose Audio Power Amplifier - NPN 
General Purpose Audio Power Amplifier - NPN 
General Purpose Audio l\»wer Amplifier - NPN 
UHF Oscillator, Mixer, RF Amplifier - NPN 
Low Frequency Oscillator, mixer, RF Amplifier - NPN 
Hi Voltage Audio Amplifier - NPN 

General Purpose Low Frequency HP and Audio Amp - PNP 
SI General Purpose Med. Current Amplifier and Switch- PNP 
SI VHF/tJHF Oscillator, Mixer, RF Amplifier - NPN 
SI General Purpose Audio AmpUHer - NPN 
ICC-724 SI General Purpose Audio Amplifier - NPN 
ICC-7 SI General Purpose Audio Amplifier - NPN 
SI General Purpose Audio Amplifier - NPN 
SI General Purpose Audio AmpllJler - NPN 
Field Effect Transistor Audio - N Channel 
Field Effect Transistor - RF-N Channel 



ICC-639 

1CC-640 

ICC-641 

ICC- 703 

ICC-704 

ICC- 706 

1CC-T09 

ICC-7I2 

ICC-714 

ICC-715 

ICC-716 

ICC-71B 

ICC-721 



ICC-729 
ICC- 736 
ICC-801 
ICC- 80 2 



51 
SI 

SI 
SI 
St 




28A8S6B/ 81 General Purpose Power Amplifier- PNP 90V 7A 90W 



Microwave RF Transistors 
Communications Corp* i 
P/N Wattage Frequency 
Dl-28 1 

D10-28 10 
El-28 1 



L38 

1.68 

L40 

L42 

L35 

L20 

L90 

L30 

2.40 

L40 

.45 

L68 

.55 

.55 

.58 

.55 

L67 

• 4b 
1.20 
2. 55 
2.15 
4.90 
2.35 
2,15 
L75 
2.10 
2.10 
2.55 
L10 
L28 
L65 
L85 
1.8$ 
L10 
2. JO 
LU 
L40 
L85 
L65 

L65 

L55 

2.15 

3.90 

4.00 

L9S 

4.00 

2.95 

1.20 

L30 

2.00 

L65 

140 

L35 

1.40 

L42 

2,15 

L85 

6.10 



400-1200 MHz 
400-1200 MHz 
1-2 GHz 



Microwave Semiconductors Corp. 
M5C200I I 2 GHz 

MSC3001 1 3 GHz 

MSC4001 1 4 GHz 

MSC4003 2. 5 4 GHz 



Voltage 
38V 
28V 
28V 



28V 

2SV 
23V 

28V 



Seven Segment Display 
Price DI^TOT Utronix COO 
1.75 MOR1DA Motorola 3.00 
19,00 MAN 1 Mansanto 3.00 

30.00 

Bird Slugs Fbr 43 

Qtf. 
35.00 4 ' 2, 5W 105-120MC 20,00 ea 

60.00 1 25W 50-L25MC 20.00 ea 
87.50 3 25W 200- 500MC 23.00 ea 
125.00 I 25O0W 2-30MC 25.00 ea 



Microwave Diodes 
Varian 
VAS21 
VAS31 
VABB00 
VAB801 
VA8812 

Motorola 
MV1S05C 
MVlfiOS 



Motorola Bridges 



Step Recovery 
Step Recovery 

Standard Bimode 
Standard Bimode 
Standard Bimode 



Power Varactor 
Power Varactor 
MV1862D Microwave Tuning 
MV1B63B Microwave Tuning 
MV1B64B Microwave Tuning 
MV1868D Microwave Tuning 



15.00 
15.00 

15.00 
15.00 
15,00 

10.00 

10,00 

3.00 

3.00 

3.00 

3.00 



MMM3r4 

MDAl 591-5 
MDA962-1 

MDAS60-3 
MDAB20-4 



300V 
400V 
50 V 
200 V 
200 V 



10 Amps 
8 Amps 
10 Amps 
2,9 Amps 
1 Amp 



Diodes 

1. 5A K100PIV 

L 5A 800PIV 

IN 9 14 

1N4148 

1NU&0 

IN270 

3000 firv 750MA 



A 



W/L50 
10 A 00 
10/LOO 



PHce 

3,60 

3.75 

2.45 

2.25 

L40 

Kss 



4 iJ &, 0, b 



CO TTL ICs 7400 Series 

7400, 7410 t 7430, 7440, 7450, 7453, 7460 .25 
7474, 74HOO, 74H04, 74H10, 74H30, 74H40, 74H53 
7483, 7495 t 7496 



10/L00 gg§SS 
10/L00 SS222 
10/L00 
LOO 



2XSX 



W 



45 
55 



& 



MC1355P .75 
MC1SI9C LOO 



102 



73 MAGAZINE 




Check these bargains and compare our deal with others... 

DRESS UP YOUR RIG and keep the XYL happy with these modern 
control heads. These are made by RCA but will work with any rig if you 
do a little soldering. 

Contains a DPST switch, and two 20K pots for volume and squelch, all on 
concentric shafts, and an Amphenol mike connector. 
The multiple frequency version contains the above plus a four position, 
two pole rotary switch, and lots of room left inside for extra boards for 
scanners and toneburst generators. 

/ ^ \ Single frequency control head only. $4.00 postpaid 

Multiple frequency control head only $5.50 postpaid ^m^ 

ADD MORE TALK POWER with these like new handsets and mikes. Both 

have a transistor preamp built in and come with coil cord and Amphenol 

connector. 

landsets in very 

ood condition ..$6.00 postpaid 

Handset hangers with built-in multiple pole switch, only $1 .50 postpaid 

Mikes only $4.50 postpaid 

TERMS: All items sold as is. Illinois residents add 5% sales tax. 

Send your check or money order today to DuPage FM Inc. 

P.O. Box 1 
Lombard, III, 60148 

If you have any questions or are looking for something special give us a call. Just ask 
for Bill Lester. Our easy to remember (for us) Telephone is 312-627-3540. 







SPECIAL NOTE TO CATALOG HUNTERS and those who like having 
price data handy for future needs: LOOKING FOR A UNIT? No matter 
what your needs are send us a postcard with your name, address, phone 
number, and a description of the unit you need — We'll do the rest — 




m 



VID 



TAP 



RECORDER 



;;:. *$ 



< 



BELL & HOWELL MODEL 2965 

This is a portable system and comes with 
recorder, camera and charger, A TV monitor 
is built into the recorder. Camera includes 
built-in Microphone and Zoom lens. 
Recording time is 20 minutes on 5" tape. 
Recording is both video and audio. 



SPECIFICATIONS 



RECORDER 



AGC Aud*o& Video 

RESOLUTION 535 l-nc*. HOP" RESOLUTION; 3001-nei 

AUDfO RESPONSE 80-10.000 Hz. 

POWER REQUIREMENTS 12V DC, 10 watts 

BATTERIES ? 3G * 3 U Rechvge^fe I net vWranreed) 

CHARGER MooV( 105905 -Built-in 2:1 EIA Sync grn#rat*r 

CAMERA: 

RESOLUTION 5?5 line* 

VERT fREQ ©OHilEIA* 

HOR FREQ 15,750 Hz 1EIA1 

VIDEO OUTPUT 1 p -p., 75 ohm. unbalanced 

WIN! ILLUMINATION: 30 Ui*. 

VIEWFINDER l\" M"CRT wfrnarjrufor) 

LENS 5:1 zoomF2-72 

SHIPPING WT 3Btb 

LIST: $1595 
0(7/? Pfl/CE (NEW) $550-00 



BELL & HOWELL Model 2966 - SHIBADEN SU700VC 

(Assemble, Edit and Stop Motion) 

This video recorder will record directly from a standard 
TV set or a TV camera. It will play back over your 
home TV set Audio may be dubbed onto the 
tape, A 7" reel (2400') will record 1 hr. No 
home VTR unit under $1000 can match 
the quality and capabilities of this unit. 

SPECIFICATIONS 

RESOLUTION 525 Unci. Standard TV or CCTV tKonJing 
VIDEO- Input uttd output I OV p-p, 75 onrm, unbalanced 

GrealL'i than 3,5 MHz ffeoj, response 300 linti 

plut Hot. resolution. 
AUDIO Mi lit- ot Sine inputs. 60-10,000 Hz freq, rangr 
POWER REQUIREMENTS 1 10V AC. 95 wafti 
DfMENSEONS; ia3/8"Wx 10 3/16" H * 15 11/16" D 
AGC or Mimupl Audio & Video gain 
POWER REQUIREMENTS 11 DV AC, 95 walls 
WEIGHT 65 lbs. 



MAI NTAI NANCE 
MANUAL $5.00 



LIST PRICE (1972) $995.00 
OUR PRICE (NEW) $450.00 

(USED) $250.00 
Experimenter's Special $125.00 



104 



73 MAGAZINE 



Please rush 



ORDER BLANK 

Bell & Howell model/s 2966 



Bell & Howell model/s 2965 



Rolls, Video Tape, 



Batteries 



,Color Adapters 



Price 



to: Name 



Shipping 



Total 



State 



ZIP 



RECHARGEABLE BATTERIES - New, for Porta Pak 



I 

$36. 00 a set. 



COLOR ADAPTERS — limited number available, will work in almost 

any Black and White VTR to convert to color, 
record-playback $275.00 ea. prepaid. 

NEW NAME BRAND VIDEO TAPES - 2400 ft. (1 hr.) any quantity 

available, shipping wt. 2 lbs. $25.00 each. 

CONDITIONS OF SALE: 

NEW EQUIPMENT — sold new, but as Is. Guaranteed to be new and in 

good working order. Replaced or repaired by us 
if found defective upon arrival. 

USED EQUIPMENT — sold as Is in good working order. NO warranty. 

All units checked prior to shipment. 

EXPERIMENTER'S DELIGHT - used as is repairable. Physically intact 

not beat to hell, but requiring some work. 
Problems and probable causes listed with each 
machine. 

PARTS — available at near giveaway prices, through us. 

SERVICE — units can be serviced by any competent video technician, 

as well as through Bell & Howell AV Service and 
Shibaden in Melrose Park, Illinois. 

QUANTITY DISCOUNT — on orders of more than 10 machines. 

DEALER INQUIRIES — are invited for sale of new equipment. 

New machines have standard Japan EIA 8P connector to mate with alt popular VTR monitors. 
Used machines have all coax and cannon xl connectors as shown in the ad sheet. Used machines 
do not have AGC or edit ability but are otherwise identical and interchangeable. 

All sales are final. Cash with order. Shipped best way. Add $20.00 per VTR and $1 2.00 per 
Porta Pak for shipping — excess refunded. 

COMMUNICATIONS UNLIMITED 



9519 MAIN STREET P.O. BOX 463 
WHITMORE LAKE, MICHIGAN 48189 

(313) 449-4367 



*v&° 



ic©' 



V 



ij^e 






a»* 



<a 



&\o 



OCTOBER 1973 



105 




NEW and SURPLUS ELECTRONICS FOR THE HAM 

and EXPERIMENTER 



SI£E: 
3.55" X 6,20" X 2.12" 




5 VDC 

3/*a AMP 

POWER 
SUPPLY 
KIT 

12,35 



USES THE LATEST STATE-OF-THE-ART THREE TERMINAL REGULATOR 
CIRCUITRY. 

HAS INTERNAL CURRENT LIMIT, THERMAL SHLTTD OWN , AND - 
SAFE -AREA COMPENSATION. 



$ iq95 



WAHL 



Greatest advance 
in soldering since 
electricity . . . 



COMPLETELY PORTABLE 

HEATS IK 5 SECONDS 

SOLDERS UP TO 150 JOINTS 
OH MORE PER CHARGE 

RECHARGES AUTOMATICALLY 
IN tTS OWN STAND 

NO AC LEAKAGE OH INDUCED 
CURRENT TO DAMAGE DELICATE 
ELECTRONIC COMPONENTS. 



COMPLETE WITH RECHARGING ST AMD r TINE TIF AND 

INSTRUCTION BOOKLET 





ALPHA -NUMERIC 

KEYBOARD 



SSOSS 

MICRO SWITCH 



MODEL 5W-10639 contains 61 #JSWU Solid-State switches 
including key tops, ROM encoded Into EBCDIC. 

MODEL RW-Q1I35 contains 56 #7A1MS Reed switches including 

key tops, diode encoded into EBCDIC, 



DIP CUP 11 \C TEST CLIP 

1 V 



FE 



POMONA 
ELECTRONICS 



MODEL 3916 




FOR 14 OR IS DUAL-IN-LINE PACKAGES 

The ''Dip Clip" sn specially dtsixnad ia hJIow 14ii attachment at 
iesl probes to 14 or 16 lead CHPS. The- unique dei»gn srtmH^ re- 
duces the po-sfirbslity af accidents aho-rtine while teilirig hw& clrv 
CuiLi, Nimirirous t«! pfuUcS may tic quickly connected fur hand* 
rr<m1r-?tin K 



MOS DIGITAL 
CLOCK CHIP 





CKE 




POWER STRIPS 

WTTH: FUSE, SWITCH, AND LAMP 



Four digit electronic clock LSI circuit In 40 pin DIP. 
Designed lor direct output to liquid Crystal Display. 
Internal options include: Alarm, Snooze, Seconds 
Display, Reset t and 24 hour operation. 








$g3D 



KJJ5EL ]l 



Other Models Available 



•Mmii if 



N 



B 



alpha-numeric 
display bezels 




Ev 


! ' 

A 

L 

■ 






1 
C 

. ■ 




















1 . 




|i 






Oft! 


L 
UNO 


B 




















DIKEN5IG* 


[ 




PRICE 




HOD&I 


*A 


■ *B* 


■c 


■D* 


1-24 


25-99 


100- UP 


90^-3 


a $ 


J UJ7 


\LV< 


'? 1.74. 


(2.2? 


2.07 


1.91 


9 1 0-3 


Ut & 


3 2.00 


U*l 


f 2 2*37 


2.30 


2.12 


t*95 


915-3 


ex M 


3 3.00 


1.1; 


'2 3.37 


2.40 


2.2 1 


2.04 


920-3 


ur. ,& 


3 £t,0Q 


1 .1' 


'2 it, 37 


2.45 


Z.25 


2,06 


930-3 


oc 1.3J 


3 5-00 


1*7; 


tt 5-37 


2.75 


2.53 


2-33 


940-3 


tx .a 


3 5,53 


i-.iti 


r£ 5,9? 


2.65 


2.43 


2.25 


950-3 


tx i.3 


3 6.50 


1,7! 


?0 6.B7 


3. 


t5 


2, 


B9 


2.67 



mm 

BGJXS 




Deluxe Electronic 

Equipment Enclosures 



WHEN ORDERING REPLACE XX WITH FILTER COLOR G0©H: 
HEUTRAL * 1 5, REE * 60i AMBER * 70, GREEN = 90 

sxamplflj 9^0*60 {Hodel 9J0 with RED FiltaiO 













UIMCNS1DNS 


6cf**n 


fttSAlE 


MOaEL 


W N. DEPTH 


Vanwd 


N£T 


"A" 


65* * t l A * 3 


h& 


3-7B 


■ r £" 


B"Jf, * 3^ * 3£ 


rto 


4.9$ 


■f 


7% k 3*; * 5 


yfrfl 


6.96 


"[}■' 


B K IW * 6 Imgblli mlg j^ll I 


yea 


»,7B 


"1" 


a^ 1 z% * 7J& 


fM 


B.l* 


"F" 


7 ! > > 4'i i 10 

10k,. * a\ * 8 


r« 


8^9 


"(j- 


m 


8-95 


,r H -. 


AH x SW* 4 


no 


a,9i 


"D1 " 


Mrq. bracket aei 1or "□" 




.35 


"HI" 


"H" Panel with maunlfld Wide Vu 
1 mi &C * 2 Rocker nrfctof 


b malar, 3Ji" 


fH.95 


"HA" 


5 1/8x5 1/2 x 4 [fliar*k Pjittl] 




6.95 


„y. 


5n] 1/3 x 5 3/4 I Sloping Parcel} 




7.45 


"K" 


4 3/4 * 7 3/B * t L W/Handle 




IJ.50 


"l_" 


11 1/fl H6 1/B x LP 3/4 




SO-^fl 


,l M" 


11 i^a « <5 i/Bx t&a/vi 




21.Ji<iJ 



OTHER DISTRIBUTOR LINES^ 



K 5 S E J\r 
y^-i - ■■■r 1 lr pi-^t-i 









J.W.MILLER Co, 







pfD)ectS WAHL 

unlimited 



HUNTER TOOLS 

1 i'liiiiiiii d> ritnhil l^iiaii'Pi 



i^IAICq 

\ 



BUD RADIO, INC. 



.°>*ih ::i :» 



WJisn 'AfiHNLH MCflOClfllMS iir»«iuiN 

iiEUidflT uiftflnEfl coflPOBflnon 



KA ELECTRONIC SALES 

131£ SLOCUM STR&eT DALLAS, TEXAS 752Q7 

iSl-ai 747-333D 
7d7-1BB2 



WRITE FOR FREE CATALOG. 

VISIT OUR STORE SATURDAY FROM 
10AM to 4 PM. LOCATED OFF STEM- 
M0NS FREEWAY NEAR OAKLAWN. 




106 



73 MAGAZINE 



Buy Af«y 3— 
Take 10*7* 

lUfltl 



^1 -5 



jNTEGRATEDl 

CIRCUIT 
SOCKETS 



* 



□ 14-Pi"> DIP 

r=i iji Pin. Wirt 



14-Pin 

3 14*P»« 

15-Plh 



Wrap 



S.4S 

.59 



Side 
DIP 



□ 16P1», Wjr*^ 



Mount 1 OO 

. .so 

.29 



Wrap 



,□ 



TO-S" » orlOj^i 



*HAM' UHF 400MC 
HIGH POWER 
TRANSISTORS 

By RCA or equal 2N3632. 
NPN. 2li watts. ft am; 
TO-tiO ease, with Mud mtR. 
\TEV max *■-"». 



$1.49 *^ 

HIGH POWER 
TRANSISTOR 3 for 53 
WITH HEAT SINK 

Removed fn«m nevi i«jn:i»- 
mi-ril! Inrhnlr^ pitptllar 
jN t 7 1 'rfrHjrkntth 1 

Tim TU '. , / ' t mjin j 1 1 in t 
i'MV I fiO \v;iii^, VCtHI 
MtV, I "i Amp**, til hfi j . Knr 
i Kta » 1 1 • »J1 « InisJi powei 1 

ft«\ r M'ilLlHt + *f "tl 



.» 



^nik "i \ 2 l 



I 1 



-AEROSPACE" 

BABCOCK & LEACH 

CRYSTAL CAN RELAYS 



12 for $3.50 



iJcrYM 



-v.V 



i i **- 



All hi j rmi»T jrnlly . ;tU-iL 

Khihmim, l/i>. half. iitnl 
fulJ cr>%stJiJ ran type* in 
<*-12-^4V in jLKst contact* 
up to ll'IH". 1 .imp up 1 1) 

,il!|[lN. Siiih t>|H ,L Hit Hi. 

J I . 10, II, 10, Li I. t§U\ 
Surry, n't HiofiHing VfjRnjreri 
ur type*, huni factory mix- 
ture* *.*<*' yi*u! (Irifjci 
usst, if > o .<ri' i' - 

minded, ill U»w jirues. 

Gl "GLASS AMP II" 
SPACE AGE FEATURE 
j&Seela critical JAN upecti, A 

ft 1 4191 'bait "t sili i it fl 

sirengili" tliat metrtJi JAN 
s\>- hmli reJmhilHy, wtili- 
si.iiHi- KValancf pttwer 

>Lirgl*N t*i IK WIlltlL, ON'fS 

;irnp raliims Willi 2 iimp 
rafuslnJille Axial lead 



T M .r PTV Sal** 

1N4245 200 £.14 

1N4246 400 2 2 

1N4247 600 .39 

IN4248 SOO .49 

1N4249 1000 59 

^siucofTrijiES 



□ 5B4 
866 



1149 
3,9$ 
7.95 



8 TRACK CAR RADIO STEREO 

TAPE TRANSPORT 

1'iTtt.nns cnmplete >-track stereo recording /p\ UY hark 
unit you find in expensive car tape lierks, Excellent 
direct replacement unit if your "wn does tiol fraction 
property. Priced to toss away old, and replace with 
new, Less amplifier. Design your own lu*(i stereo 
system* around it. Uses Standard fi-tracli cartridge. 
With hi-fi sttrecj tape and nil its mechanical parts 
tliiit eti with it. Operate* uff I2VDC, Automatic track 
Locating and rhuiigmj? plus truck Indicator output. a 4 



8 



ips speed. WOW and KLrTTKK less than CI Ml' 



metM shield riwrtoi reduces motor 
nnf, I'.ses .separate 73D pn-anip 



noise tn an inaudible 
and is ready In 
Size r> x . 



Low**! Pricei ^^ " ' ' -N^ — _ 

S»«t Selection TTL ICV 




Bra 

Type 

D SN740O 
D SN7401 
D SN7402 
D 5N7403 
n SW7404 
Q 5N7405 
□ SN740S 
] 5N7407 
; SN7408 
SN7409 
SN7410 
5N7411 
I SN7413 
; SN7415 
I SN74I6 
I SN7417 
5N7420 
SN7421 
. SN7422 
_ SN7425 
SW7426 



Sale 

SO. 30 

.30 

.3D 

.30 



-5S 
-55 
.35 
.35 
.30 



.95 
.55 
.55 

55 
.30 
.35 
.35 
.30 
.37 



Factory Marked 



DIP" Pichjff 

LI SN7430 
Q SW7432 
LJ SN7437 
Q SN7438 
SN7440 
l_ v SW7441 
. SN7442 
DSN7443 
: SN7444 
D SN7 44S 
Q 5N744G 
Li 5N7447 
LJ SN7 440 
._ SN7^50 
SN7451 
-_ SN7453 
G 5N7454 
Q SM7460 
■ J SN7461 
._ 5N7 462 
G SN7464 
Li SN746S 



•■ Ordei b> sumfaerl .sn,, mbmmti 



30j.. SN7470 



30 

.60 
GO 

.30 
1.40 
1.25 
1.35 
1-35 
1.35 
165 
I 50 
ISO 
.35 



,50 
-35 

.35 



.50 

SO 



U5N7472 
SN747 3 
SN7474 
C SN74 75 
SN7476 
SN7477 
SN747S 
(J SN74S0 
U SN74S1 
U SN7482 
SN7483 
U 5H74SS 
Q 5N7486 
I SH7489 
5N749Q 
SN7491 
U SM7492 
. SN7 4 93 
. SH7494 
_ SN7 49S 



. 



. : SN7496 
A4an«y Bach Guarantee 



.45 
.35 
,52 

.95 
.55 
130 
.95 
.75 
1,15 
.95 
115 
1.41 
.55 
4.25 
1.30 
l.SO 
1,10 
1.10 
1-iO 
1.10 
1 io 



D SM7 4104 

D SN74105 

5N74106 

., SN74107 

^_i 5H74108 

i . 5W741I2 

SN74113 

I SN74H4 

BSW74121 
5N74I22 
[ SN74123 
SN74139 
SW74140 
SN74 145 
SN74148 
SH74151 
5N74153 
SN74154 
SN74156 
SN741ST 
D SN74158 
D SH741SO 



u 
LJ 



»»n reftneat 

.55 
,55 
1.25 
.60 
1.25 
1.25 
1.25 
1.25 
.70 
.75 
1.20 
1.50 
.50 
1.40 
4.50 
1.25 
1 60 
1.95 
1.42 
1.55 
1.55 
1.95 



o\LY 

SN74161 
! SW74162 
J SN74163 
5N74164 
Cl SM74165 
} SN7 4166 
1 5N7 4174 
SN7417S 
C SN74176 
: SN74177 
; SW74179 
1 SN741SO 
SN741B1 
SN74182 
SN74192 
SN74193 
SN74194 
SM74195 
SN74196 

SN74197 
SN74199 



1,65 

1.95 

1,95 

3.50 

3.50 

2.05 

2.10 

2.10 

2.10 

2.10 

2.10 

1.20 

4. SO 

1,20 

1.95 

1,95 

1.95 

1.35 

1-50 

2.10 

2.65 



KRONOSSi|7 # - 



Buy lOQ _ Take 20% 



Buy 3 
Take 10% 

Cabinet: 
All "MAN" 
Type 



sei vinKlc* National MQ5 "clock chip" 
12 or 24 Hour operation readouts 7 segment type* 
I **■ - ij^tinl i'. ,r s« nfHifu lii eajfineeTM ii- tin- mi 

,ul..iin*"1 difiiinl timing de\je*' in llie « >»n^tjrnet limt^ 
MeJd, h irt Mt i' 1 iTiiU K,KONl>S KKJmi Snir.H, in 

tu*- ni'Vk >ii^-k tdl^purpitae w*almii-und-hUu*k nirjdern de- 
ttitrti i.ilnni'1, enhanei - any iiI(mi<, ht*me k den. etc. It h< 
■ u "\ i-sible-iitt mri n*nver?iiition pie**< where vi 
STAN 5ARI3 TlT ' i''-* r, "d. tUi.s nidiJt'rn L>l \atinnal c lut-k C'lup, .irnl 

• patfe broithuf^ L'hwfc full wiiU picit>nat> and r,^y-i'»- 

CHRONOMFTFR Jlu> ' ' >m '> ^H-p4i>->Up ni»tnn tmn^. Tint* Kit i> t'U.M- 

c Vi/ c> r ?h """iM-TKlt SlMl*tlKIKU raaktnjt do-it-youra«lf *?w*y! Utini 

** li.ULir*^ iiltlufic ,i * I 1 inn itfntniLs, i lunir \n\ iceoiul, 

i ntiiiutr per ><■< ond, atid hold huttori, Ka«y-to -change 
from I J in 2 1 a our*, i I (^ li di^M.s. ," f ii to \\\\ h% utieru- 




Any 
Type Clock 

TIME 



readouts 
LED 

101 MAN-3 

102 MAN-1 

103 MAN-4 

104 Nixie 

105 707* 

106 704** 

107 SLA-1* 

108 Same as KR 



by Monsanto 

Char. Siilo 

.12 547. 

.27 47. 

,19 47. 

.45 47. 

.33 47. 

.33 47. 

.33 47. 

-107 except 



add 512, for green digits* 

*Litronlcs or Opcoa equals to MAN-1 char 
**Lltron4cs equal to MAN-4 characteristics 



COMING SOON: Scientific Devices 
low-cost Crystal Standard, watch for it 
TWO CLOCKS IN ONE! 



LINEAR 



• FACTOWV 
QUAHAMTfCO 



Op flmps 

|r*CTO»y TESTEtfl 



FACTOeV 

hahkip 



NATIONAL 'OP' AMPS 

10% 



Type 

L. LM 
LM 
LM 
LM 

LM 



300 
301 
302 
304 

305 



QLM-307 

LM30S 
j LM-309H 

BLM.309K 
LM-311 
] LM 320 
; LM 320 
' LM 320 
: LM 350 

D LM-37© 
] LM 37 1 

' LM373 
D LM-374 
a LM-380 
Q LM-3070 

LM 3071 
♦TO-3 ca 



BUY ANV 3 TAKE 

Description Sale 

Super 723 V. reg. ,-,.-,-, -$1.49 

Hi -performance amp , . , .49 

Voltage follower ... 1.49 

Neg T V. reg 1.49 

Pos. V. reg, ,..,..... 1.49 

Super 741 . . ..,,--- .59 

Hi-Q Fet Type Op Amp . 1.50 

5V 200 mil V. reR 1.50 

SV l-amp V, reg.* - - 2.25 

Comparator . , , . 1,50 

Minus 5V lamp V.R.* . 1.95 

Minus 12V lamp V.R.* 1.9$ 

Minus 15V 1 -amp V.R.* 1.95 

Dual peripheral driver . , .59 

AGC squelch op amp . . . 1.49 

R-F, l-F* op amp 59 

AM-FM, SSB, I.A.D, 3.75 

AM-FM. S5B, IVAD 3.7 5 

2- watt audio amplifier - 1.95 

Chrome regenerator . , 1.50 

TV chroma IF amp . l.SO 
e, — other* TO*5 



i 2 ir.-.{*2^ 



Terms: „i«M ptiMuffe Rated: tii-i :tfl 
Phone i if *i»*r> Wakefield, Mios. < i> t \ a-i »-*sffj£ttj 
Retail: I H- I N l*td Carmine St., WakrlteJrL Mil*-, 
lull Water Strt-t-t > < n.K> MAY |€|-: 1'ilOXKH " 



iHIGH VDLT UMP | 

PIV SALE 
2000 s 1,00 



! 1 
I l 
■ I 
D 

a 

a 
n 

□ 

! J 
! I 

I 3 

a 

a 

a 

a 

p 

a 
p 

a 
n 

n 



n 
a 

□ 

n 
i 

□ 




531 Hk slew rate op -amp (TO-5) . . 

532 Micro power 741 'TO-5) . ... 

533 Micro power 709 (TO-5) 

536 FET Input op amp (TO-5> , . . . 

537 Precision 741 fTO-5) 

540 70W pwr driver amp (TO-5) . . 
550 Precision 723 voltage reg, (DIP) 
556 5 Times fatter than 741C 
558 Dual 741 (mini DIP) 
5S0 Phate loefc loops (DIP I 

561 Phaitt loch loops (DIP) 

562 Phas* lock loops (DIP) 

565 Phase lock loops { £ i 

566 Function generator (A) 

56 7 Ton* generator (A) - 

595 Four quadrant multiplier . - . . , 
702C HI grain. DC amp (TO-5) . . 
703C RF.IF, amp, 14 ckts (TO-5) 
704 TV sound IF system 

709C Operational amp (A) ...,,,.. 
709CV Op amp (mini DIP) ......... 

7 IOC Differential amp (A) ........ 

71 1C Dual dlff, comp (A) 

723C Voltage regulator (A) 

7 33 Diff, Video Amp 

74 1C Frequency compensator 709 (A) 

741CV Fr*q. comp 709 (Mini DIP) . 

747C Dual 74 1 C (A) 

74 8C Freq. adj. 74 1C (A) 
7 4BCV Freq, *d|. 74 1C (mini 

7 53 Cain Block 

709-709 Dual 709C (DIP) .... 
739-739 Dual stereo preamp . . . 

741-741 Dual 74 1C (A) 

751 SO Dual peripheral driver . . 
75154 Dual peripheral driver . . 
745512 Dual line driver ... 

PA265 5 Watt voltage regulator 
ULN23O0M Op amp with SCR 
CA3065 VttiaG Audio system - • . 
iAi TO-fi or DIP dual in line pak 



DIPj 



$2.50 
2.50 
2. SO 
3.95 
2.50 
2.50 

1.17 
210 

1.00 

3.25 

3.25 

3.25 

3 25 

3- 25 

325 

3.10 

-49 

1 00 

1,50 

.49 

.49 

,49 

.49 

.95 

1.75 

.49 

.49 

1.25 

.49 

.49 

1.75 

too 

1.98 

1.0O 

.88 

.88 



1,95 
1.50 
1.50 



ISC CATALOG on fiber Optics, 'Its'. Semis I 

POLY 

P.O. BOX 942A LYNNF ELD. MASS. 0194c 



r 3000 

D 4000 1.65 

5000 225 

6000 2.96 

8000 3.50 

10000 3.95 



i 



HI Fl 1 SQUARE 
MINI METERS 

■ Plaitic case $1.49 

• Red ni-itllf Indicators 

Bttlnm inis t tereo, tape, amps. 
VI", niile miff, plu> ;l minttA 2tt dh, 

n v l"» fruni Hiig, ptiiH ;i mlniw Ju 4b, 



'!=* 



e»i 



r -i 



• -' i 



(or S3.75 



OCTOBER 1973 



107 



F2* 



Southern 



x 



Hospitality 



For hundreds of years, the South has been famous for its 
hospitality and friendliness. Rex Johnson offers you the finest in 
new and used gear, along with service and follow thru in the true 
tradition of the South. 



fir)(i : ) 



• • 






Write us for our Free Used Equipment List and 
trade-in quote on all Major lines. Remember, 
the Southern tradition of friendliness and 
hospitality is alive and well at Johnson 
Electronic Sales. 

P.O. BOX 332 GRIFFIN, GEORGIA 30223 

(404) 228-3831 



JOHNSON 
J ELECTRONIC 

S/UES 







" LITRONICS-MONSANTO-OPCOA 



LED Readouts 



MAN 5 
MAN 8 



SLA- 1 

SLA2 1 
5LA-3 



All tit 14-fiifi 1* 

r,v 1 n to 2n rmK o.t« i 
nt-rat*. n\un letter* hV 
ijt-cimaL With M't" *hei ' 
* M n unto KijiijlI. MAN- 1 
■■ 'MAN- I Kpel 
f,,Tn-l)tno!e Array, 

MONSANTO 

"ALL LED M T *P* 



MAN 



MAN-3 



SLA-3H 



Size: 



MONSANTO MAN-l* 



27 



MONSANTO MAN-2* 



32 1 Red 



MONSANTO MAN-3* 



.IIS Red 



MONSANTO MAN-3* 



1 15 



MONSANTO MAN-4* 



MONSANTO MAN-4- 



MONSANTO MAN 5* 



27 



MONSANTO MAN 8* 



Color . 
Display Decimal 



Red 



Red 



.190 Red 



190 Red 



•Gfeert 



.27 Yellow 



Ye* SN7447 4. SO 3 for 512 



Ye* 



Y«i SN7448 ! 2,25 3 for 56 



No 



No 



Ye* 



Ye* 



Driver 



Each 



2513 6 SO 3 for $ 18 



SN7448 1.49 3 lor S3 



Yes 5N7 448 2.95 3 for $B. 



SN7448 



5N7447 G.50 3 for SIS. 



SN7447 6. SO 3 for SIS 



spccui OAK FEATHER 

I ibi r - _ •— — -— 



REFLECTIVE LITE BAR" (SEGMENT} LEO READOUTS! • * # ' Decimal n^lil ur left 



LITRONIX 707** f MAN 1) 



33 



LITRONIX 704**+ JMAN-4) .33 



J OPCOA SLA 1** (MAN 1 t 



,33 



OPCOA SLA-1** < MAN 1 I 



.33 



OPCOA SLA-3H Giant Ditit 



70 



Red 



Red 



Red 



Red 



Red 



OPCOA SLA. 2 Plus/MJnu*/l .33 



Red 



OPCOA SLA- 11C I MAN 5| 



33 



Green 



OPCOA SLA. 12 P|us/Minu*/1 .33 Green SN7447 4.95 3 for 512 



Yes | t 



Yea 



Yes 



No 



N, 



• * * 



SN744B 3.50 3 for 59 



5N7447 3. SO 3 for 59. 



5N7447 1.95 3 for 55. 



Yes SN7447 8 60 3 for 524 



SN7447 3.50 3 for $9. 



5N7^47 4 95 3 for 513 



RRV 



m 



RANGE 



t « 



P 



3 for 515, 



TWIN DIGIT ARRAY 

Tyg* SP3&2, each ilicit is 
mciiv nluaU)' mm ml ted. op- 
erates off isovm\ infl 

ua. 200 tnw. Color: 0KANU&. 
7-digil , class protection 
uvi-r digits * harac fcer 
height: D*t(3. P.C r mount - 

i UK, .Hi/c: ' t ■" K ' \" , D*pfna 
npr digit. Driver: SNT447, 



RTTY 

nted 



To 
•Pri 

For Unique Panel 



Jrcuiti 



TOUCH 
SWITCHES 

c - Sal* 

Switches j, 49 

No. 

G 0* 



1.79 3 for SS- *"*• ^P "AK Uf um 



KTTY, too* 



& nuu- 



" U 3* 

board n 4* 

•wily 4.4 V * to S 7 * 
Printed circuit. n a * 

jviiiif top. hia^k uamhei, 9 ** 

1 "ft or ir .,„,„ , wtteh „a _y 

'Of keybo ard 57.50 D 4 = 

r 

3 xt 



B 




LED GaAs INDICATORS 




y 



2-MVl*. Ambe-r, viaiblir jumhn ftpuKy Jen* upright, ... * 

1-MV2*, TO-1 B, Dome, .green, visible . . . 

| l-MV-2*, pret-n small dome, green cliff, tit* 

Q l-MV-2*, clear *mall plastic dome, green ill It. lite . . 

1MV-3V micTQ-mii|l pin head' dome, T<)h, j*reen |i t«- 
u 3-MV3*, uMblf. "Vu-iv pin pafc" . tr-ri, mi nr dome lep- 
P 1-MV4*, mod, Ingh power, red, 2-uL'utt* ..*.... 

Q 1.MV4H 1 , stud, high power, hi-dame, red. 2-wntts 

3 MviOB, rhtih!*, rt-«i, clear, dome len- r TO- 18 

2 3-MVlDC \ -bit-. ri-iL diffused, dump tens, TO- I ** . 
tl 3-MV5G*. ttxlitl Lt-.id»» micro- mini dome, clear, red , . 

3 3-MVSQl2* ( n si bit-. rer|« small d+irm- tem 

3MV5022*, jum.hu red dome, TO* 18, visible 

I 3-MVS020*, jumbo cl^ur dome, TO- 18, visible, red . - , 

IH 1-MV5040*, i-LED red array, with 5-tea(i puk - , 

] 3-MV50S4*. visible. per4, fumbri dome lins, upright . . , 
] 2-MV5080** TOrt.H« mifrn-rm ni, clear dome, red . 

4-MV50B2. visible, ristl. I* tear flat l*n«i, To- 1 h . 
; 1-MV5222*, fSTcvrt tu MlfLsiii dome, ■! Hi. ed cretin llti 
i 1-MVS222** dear hi dome, ditf. tfn ■» li hi< 

3 1-MV5222*. jumbo dome, green, oanel snaD-in .,,*.. 
r] 1-MV5322*. jumbo dnrnr, Ga.Asp. panel Ktiap-in Vellow 

l-MV9000* t nuirifllfr |ian*-t iamo, s*^i|ci(. r*d* < le.tr lens 
2-MT-2*. i*!n»to Tt.iii- Iiplil -i-n-«»r. TO- i ^ 

□ 2 -ME-l-. mfra-red. pA r&n "l |C lei**, pin type .... 
"3-ME-4*. infra-red. ^aible". TO- 18, ,liff. dome 

Z3-ME60* t infra-red. "invisible ", axial, rrncro-mini 

MUX'D DIGITAL CLOCK PC BOARD 

Your choice 



4 


r 

$1.00 


1.00 


1 00 


i-oo 


1-00 


1.00 


3.95 


3.95 


1.00 



3 for 
527 



9.95 



O 




1,00 
1.00 
1.00 
1,00 
1 .00 
1.49 
l.OO 
1,00 
l.OO 
l.OO 
1.00 
1.49 
1.98 
1.49 
1.00 

l.OO 
l.OO 
l.OO 



h h-j.irii property uiljIti- 

p!r\fd fur tl rtinits, tn ti« *] i E 

MAN-'lV. MAN-.r« ( MAN- 

i > t Lftrimict; T 07 i M AN. 

I \ rind TO I iMAN-ii, and 
llpi . . ; i. - RLA- t '\1A\-! I 
Jh.:iid fi m " |i»BfE with *pl*C 



!'■• I 




$2.50 

I MAN-l pUtronlcs 707 IMAN-1*) 
MAN-3 I ! Litronics 704 (MAN-4*; 
! ' MAN 4 I I Opcoa SLA 1 (MAN-l* \ 
D e-MAN-3A"» for abov* 
board. 59-50. 



G Etched calculator burnl CA LCU LA X OR 

with hole«. as above, leas mM^m^Mw^***. M w^m*> 

switches $2 50 Board §j FY KflflH } 

Properly etched, drilled 4 "MULTIPLBXEO/* with proper 
di . Heady \>» no! Lsed with i^gr own CAL TKril'* 

ifOOl chip £iHvertm«Mt at $ if equ^l to Oil Tech 

*tt Mmhifh. chip. Keyboard use* the new manufar lured 
by OAK* prmted-circuit low-profile FEATHER TOITH 
>witt-hi-s. f>-tti-9 in white with black letters. l>eciPial 
white with black dot. t*K, CL und the 4 function 
n witches ure in blue with whin ir&cterti. DeMjcned 

bv tup maker. Si?:e: fiVa * ** ! 'n >* ' '". All etched rnn- 
rii<f h t]iiiis link tn take a 12-pin t?djte ronnectnr. 
D Cal Tech 5001 l ^-tlifCil calculator ^w-pia DIP for 9.95 
II Keyboard, 50OI -i-hip"\ and 1^ MAN-iKs, specs 35.00 

1 Twelve MAN-3's fur iibuve 17. SO 

] Twelve MAN-4"* f<ir above . 32. OO 

_J Twelve MAN-Ts fur .iliove ,. + ....... . 42,00 



9.95 

3 for 527, 




KJer i - har. >ume OJi Monsan!-- devices MAN-l or t 



Hi \tnHT 
MAN-l 
MAN-4 
707* 
704** 
SLA-1* 



•Vour choice of 5 
red LCD readouts! 

Only 
Buy 3 






9.99 



t ii.ir. Maker 
.27 h. Monsanto 
.19 h. Monsanto 
.33 h. LftronJct 
.33 h, Litronics 
.33 h. Opcoa 

Scteniitit" ||evici 'Ihcttal < .ntmi: M«m1uIi ltp«r- 

forrii any other IH_'M *m the market today' More fea- 
titre* ih.in • i before' Not u tj*. not tncanileM-i-nis, 

-^ nut nixie bm the mv»dern LKI». * - from such fatuous 

LED manufacturer* a* Mon^anhi's MAN-L* M.W-l. Litn>nics 
f^\# TOT and Til 1. 0pcaa*4 SLA-1 i Lhi- last 1 having i ha rut- 
r i-r rtefohtM "f iK'd'A at no extra ctiarftel. Each kl1 in- 
■t-l'jdi ■-. £Mi" p t o board with (inner* for ii FREE ciise 
connectorg side-rnuuittlnif dil* nocket, LEU readout ^f 

(T\0 rUI ,r choice, rc-^itn.^, 'A M ' ^. and Mnles conneclor-s 

a-Fl^nn [%hi9 ELLMINATES iLUEJtl-NC Yni \i If and 

booklet. INCLUDES P-C, EDGE CONNECTOR — FREE! 
" Pin-for-pilt MAN-l. ■ * Pin-for-pJT) M \N-I ele< . . i'lut. -arne 



«- CALCULATOR ON A CHIP| 

D| GIT q CT5001 Chtp D 

Similar in Mo*tel< I rforrom T 

ditt rAfSlHOi. A i»-pin t»lP. Add*, multiptie*. 
>uhtr.iitr, .iful divides. Ise wiih 7-segrnent 
readout*, ,\t\ifs, and L£D"«, We jpriude BChe- 
», iiifitrortiofu t<» huild calculator 

CT50O2 9 Volt version of above 59,95 

CTSOOS-Same as above with MEMORY $14.95 

" RATIONAL EQUAL "DIGITAL 

CLOCK on a CHIP" 

Any "Chip" 

SI 2.88 

* Money Back Guarantee! 








DIGIT 



l5 v C*tU06 

,nf^ f0otlCS 

parts 



Terms: ,mI*1I fp«»-^iic:*- Rated: m-t JO 
Pboae Orders: Wakefield, M BITi 245-1829 

Retail: 1 i.- 1 N l»el Carmine St, . Wakefield, Mnu. 
loff WuUr Street i f,i>.l>. > MAY BE PHONED 

POLY PAKS 

P.O.BOX 942A LYNNFIELD.MASS 01940 



}5311 26-pin, ceramic, any readout, 
G-digitS: A-B D 
__5312 24-pin, ceramic, ^t%y readout, 

4-diKit*: C-f> 
OS313 28-pm, ceramic, any readout, 

6 diRits: AC 
a 5314 24-pin, plastic, LED and 

incand^escent readouts, 6-dlKits; A-B oflVG I 

Code. A^ — Hold Count. C — I PPS Output. 
B — Output Strobe. D — HCD 



$12.88 *Wi*J1 

512.88 Spec 
512.88 Sheet ! 

512.88 



STUD 

'TRIACS' 



POTTER BRUMFIELD Your chai „ 
MINI CAP RELAYS 

$2*49 3 for 56 



Q 115 VAC 
a M VDC 



Mi [inures only ' i x 1 v 
1 J ^". Plastic eaaed. Uke 
KNP tvpe. For pr huard nr 

kt-t, 1-1 itlfl 1*H/ - 

fttud too! llolh IFDT, All 

amie construction^ 'i 
aftijt>, rontart»> For r-f ant, 
>witchinir, \\ t. 1 -i*?.. U her- 
ever space <s prime, yoti 
neeil a "mini cap*' relay, 



OCTOBER 1973 



109 




SUPER-QUAD 
FIBERGLASS 

ANTENNAS 



COMPLETE KITS INCLUDE 
HARDWARE. WtRE, ALL 
MOUNTS, BOOM, 



STRONGER AND LIGHTER 
THAN ALUMINUM 



MAXIMUM GAIN 



AVAILABLE IN A COMPLETE RANGE OF KITS 

Special fnstunjtion Munuul un 
Kirks "Super Quads" $200 

• 2 3 4 ELEMENT TRi BAND 

10 IS 20 METER . . A MATE UP NET F ROM $129 95 

- ? 1 4 ELEMENT DUAL BAWD 

10 15 OR 10 6 METER AMATEUR NET FROM ( S77-95 




• 2 ELEMENT 40 METER AMATEUR NET 

• UHF 4 ELEMENT 2 OR 6 METER 
AMATEUR NET FROM $54.95 



S389 95 



ANTENNA MOUNT KITS 






COMPLETE PACKAGED KITS INCLUDING 

SPIDERS OR V SUPPORTS • BOOM TO MAST MOUNT 

■ ALL NECESSARY ASSEMBLY HARDWARE 

• INSTRUCTION MANUAL 

HEAVY DUTY CAST ALUMINUM 



DL-1 
DL 2 
DL3 



(2) 

(1! 

ft) 

in 

(2) 
ID 



DELTA LOOP MOUNT KIT 

IVj" Hub V -Supports 

1 '4" Boom 1o iVi" Mast T-Mouni 

2" Hub V Supports 

2" Boom to V/" Mast T Mount ; ; 



QM-1 
QM-2 



QM-3 
QM-4 
OM-5 



(2) 
(13 

(21 

(II 
12) 

ni 

(2) 

(11 

(2) 

(1) 



3 Hub V Supports 

3? Boom to 2" Mast T Mount 

QUAD MOUNT KIT 

1V." Hub Spiders (Small Spfder tor VHFl 
1%" 8oom to Va" Mast T -Mount 

1%" Hub Spiders 

(Heavy Spider tor 6M St 10M) 
V// Boom to \ l A " Mast T Mount . , . . . 

Wt" Hub Spiders 

\-&" Boom to VA n Mast T Mount 

2" Hub Spiders 

2" Boom lo 1%" Mast T- Mount 

3" Hub Spiders 

3" Boom to % Mast T- Mount . . . . . 



Net $10.85 



Net $13.75 
Met SI 4.65 
Net $22.45 
Net S3G.95 



KIRK'S 



BRAND 
NEW 



ALL- FIBERGLASS 



HELICOI DAL BEAMS 



AVAILABLE IN: 



2 &3 ELEMENT - 40 METER 

2 § 3, 4 & 5 ELEMENT * 10-15-20 METER 



CHECK THESE OUTSTANDING 



®» 



ALL FIBERGLASS 
ELEMENTS & BOOM 



ELEMENT LENGTHS 25% 
1 ' ^ TO 35% SHORTER THAN 






METALLIC AftflAYS 



PRECISION CONSTRUCTION, 
MINIMUM ASSEMBLY TIME. 

NO TUNING 
MO ADJUSTING 




I 



AND EXCLUSIVE FEATURES: 



COPPER TAPE. SPIRALLY 
WOUND ELEMENTS 
COATED WITH DURATHANE 

VSWR LESS THAN 1.5 AT 
UPPER A LOWER 
BAND LIMITS 



GREAT STRENGTH 

AND VERY LTGHT 
Example: 

i Element 40 M - 4£ Uj*. I525.00 

3 Element 5?0 M~ !7 L&*. *21&,9i 

3 Element li M 9 L13S. tl6<5-9b 

■; L lement tl> M ft L-bi. $!*'>. 9i 




<© 




MO** 

WJM§ 



WORLD'S 

FINEST 
BROAD BAND 



Kirk Broad Sand Baluns 

are designed for match- 
ing 'an unbalanced 
line, such as coaxial 
cable, to a balanced 
antenna to produce a 
symmetrical wave form 
of &qual intensity from 
the current cycle. 



BALUNS 



1:1 Or 

1:4 
RATIO 




Kirk Batons provide the greatest breakdown 
insurance by use of mylar insulation between 
the tough poly thermaleze winding and the 
Fernte Core and a final dip coating of low 
dielectric impregnation Handle peak power of 
2000 watts provided ratio error is low. 

Unique in design. Kirk Etaluns 

are produced in two distinc- 
tive models: One for Djpoles. 
and one for Beam Antennas. 



NET PRICE 

«12» s 




vm 



Application frequency Coverage & Power Rat- 
ings For I lie Various Hade Is Shown Below 



MODEL 



APPLICATION 



F/HC. 



POWER 



5075-S 
5075 -LF 



Dipore 3.4-S2 mns 2K PEP 
Beam 3-4 52 mts 2K PEP 

Dipole 1,7-10 mes 2K PEP 



MODELS 

507 5-0 

& 5075 -IF 

Far DiDtfle 

Aricrinas 

Ntl Wt. 7 Df. 




MODEL 
5075. B 

For Beam 

An tennis 

Net Wl. 7 Oi. 




WRITE FOR FULL INFORMATION. PRICES DO NOT INCLUDE POSTAGE. 

PRICES ARE SUBJECT TO CHANGE 

KIRK ELECTRONICS DIVISION 

ELECTROTEC CORP. Dept. K 

73 Ferry Road Chester CT 06412 • Telephone: (203) 873-8643 



110 



73 MAGAZINE 



know this sign 




To most people this is a symbol from 
Greek mythology. But to hundreds of 
thousands of active amateurs, Pegasus is 
the symbol of the Radio Amateur CALL- 
BOOK the single most useful operating 
reference for active amateur stations. 
The U.S. Edition lists over 285 r 000 Calls, 
Names and Addresses in the 50 States 
and U.S. possessions while nearly 200,000 
amateur stations in the rest of the World 
are listed in the DX edition. 

Both editions contain much other invalu- 
able data such as World Maps, Great 
Circle Maps, QSL Managers around the 
World, ARRL Countries list and Amateur 
Prefixes around the World, Time informa- 
tion, Postal Information and much, much 
more. You can't contest efficiently, you 
can't DX efficiently, you can't even oper- 
ate efficiently without an up to date 
CALLBOOK. 

To make the CALLBOOK even more val- 
uable, three supplements are issued each 
year which bring your copy completely up 
to date every three months. These are 
available at a modest extra cost. Full de- 
tails in every CALLBOOK. 

Get your copies of the big new 1973 
CALLBOOKS today. 



US CALLBOOK 

(less service editions) 

Just $8.95 
US CALLBOOK 

(with service editions) 

$14.95 

Mail orders add 50 r l 



DX CALLBOOK 

(less service editions) 

Just $6.95 
DX CALLBOOK 

(with service editions) 

$11.45 

per CALLBOOK postage 



and handling. 

See your favorite dealer or send today to: 



RADIO AMATEUR 

ca 






lib 



oo 



k 



INC. 



Deot b 925 Sherwood Drive 
Lake Bluff, III. 60044 



MINIATURE METER 

0-100 v A {approxj - 14" dia. 



1 ¥ ¥ F 



..,$1.00 



MINIATURE POWER SUPPLY 

Output 6Vdc- 100 Mils _, . m $1,00 

5 Volt ZEN EH and Electrolytic for 5 Volt supply furnished for 
$1.00 additional. 



REED RELAYS 

6Vdc-SPST-%x 1" $1.26 

12 Vdc - SPST - 1% x %" . . . , $1.50 

FULL WAVE SILICON BRIDGE RECTIFIER 

200 PRV (line) 25 Amps - V'sq $2.50 

OIL CAPACITORS 

4MFD-3KVdcG + E i 23F44 

4x5x4-7 lbs. ea. ,,,,.«, . ,2 foe $10.00 

100 MFD 1 500 Vdc - Sprague F1 537 
Use 2 in series for 50 MFD 3KV 

13 x 6 x 5 25 lbs. ea , 2 for $25,00 



POWER SUPPLY 

Input 1 15V/ 1/60 Output 28 Vdc 50 Amps filtered 

Silicon studs — Cased transformer and choke 

21 x 1 2 x 7 — 1 50 lbs $90.00 



.\Jlfr 



OMNIBUS Elechonic Ondu&biie& $ Uric 

3W CANAL ST., NEW YORK N, Y. 10013 12121 226-36931 




In this issue, do you think there is a need for 
more 

Simple construction projects 
Complex construction projects 
General interest articles 
Humor articles 
Specialized columns 
Operating news 

Comments 



Yes 


No 


□ 


□ 


D 


□ 


D 


□ 


□ 


□ 


d 


□ 


□ 


□ 



OCTOBER 1973 



111 



READER SERVICE 

Please either tear out this list of advertisers and send it 
in to 73 with as many boxes checked off as you would 
like to see brochures, data sheets or catalogs -, . . or 
else make a copy and send that in. Include your zip 
code, please. Send money directly to advertisers. 

ADVERTISER INDEX 



D 


Amateur Wholesale 


75 


□ 


International Elec. 72 


□ 


Antenna King 15 




D 


Jan 59 


□ 


Antenna Mart 63 




D 


Janel 32 


D 


Ascom Cover 1 1 




□ 


Jeff-tronics 53 


• 


ATV 58 




□ 


Jensen 53 


a 


Autek Research 12 


□ 


Johnson 108 


a 


A&W 97 




a 


KA Sales 106 


a 


Babylon 98 




D 


Kirk 110 


D 


Callbook 111 




a 


LA Elec. Sales 88 


a 


Circuit Specialists 


94 


a 


Larsen 18 


a 


Clegg 30, 38 




□ 


Linear Systems 41 


a 


Com, Unlimited 1 


1 04, 10B 


□ 


Meshna 90, 91, 92, 


D 


ComSpec 12 




a 


MFJ 58 


a 


Cornell 52 




a 


Milliwatt 63 


a 


CushCraft 46 




a 


Morgain 12 


D 


Data Engineering 


85 


D 


M-Tron 52 


a 


Demon 82 




a 


Newtronics 48 


a 


DuPage 103 




a 


Omnibus 111 


p 


Dynamic Elec. 5E 


I 


a 


Palomar 32 


a 


ECM 53 




□ 


Pemco 87 


□ 


Electronic Distr. 


12 


a 


Polypaks 107, 109 


1 1 


Erickson 50 




i j 


Q-Tronics 71 


a 


Fair 52 




a 


Regency 42 


! 1 


Freck 63 




• 


RP 58 


D 


GAM 95 




□ 


Savoy Cover 1 1 1 


a 


Gateway 78 




a 


Selectronics 83 


a 


Genave 80 




D 


Sentry 9 


□ 


GLB 52 




D 


Signal Systems 79 


a 


Godbftut 96 




D 


Solid State 86 


a 


Goldstein 76 




□ 


S&R 102 


D 


Goodheart 62 




D 


Stahler 63 


a 


Gregory 66 




a 


Standard 3 


D 


HAL 71 




a 


Tri-Tek Cover 1 1 


a 


Ham Radio Center 


89 


a 


Vanguard 99 


a 


Hatry 71 




D 


Venus Scientific 24, 


D 


Henry 36, 56 




a 


VHF Engineering 81 


□ 


H&H Engineering 


52 


D 


Waller 84 


n 


Hobby Industries 


28 


a 


Wolf 63 


a 


Hy-Gain 100, 101 


D 


World QSL 53 


a 


ICOM 64, 65 




a 


Yaesu 16 




73 Stuff 










FM Atlas 


59 






How to Use FM 59 






Subs 


73 








Books 


> 74 




Coupon expires in 60 days 



93 



25 



not solicited. Correspond 
OCTOBER 1973 



* Reader service inquiries 

directly to company. 
Mail to; 

Reader's Service 
73 Inc., Peterborough NH 03458 

Please Print or Type 



Name 



Call 



Address 
City _ 



State 



Zip 



PROPAGATION CHART 
J.H. Nelson 
Good (Open) Fair ( □ ) Poor 

October 1973 



(O) 



SUN 



MON TUES WED THUR 



FRI 



SAT 



12 3 4 5 




7 8 {9} 10 11 12 13 






13 (15) £2 



11 18 19 20 




H Hi 






Possible aurora 24, 25, 26, 27. 



EASTERN UNITED STATES TO: 



GMT: 


00 


02 


04 


06 


OS 


ID 


12 


14 


16 


IB 


20 


22 




ALASKA 


14 


7 


7 


7 


3 


3 


3 


7 


If 


14 


14. 14 




ARGENTINA 


14 


7 


7 


7 


7 


7 


14 


21 


21 


21 


21 


21 




AUSTRALIA 


14 


7B 


7B 


7B 


7B 


7B 


7B 


14 


14 


T4 


14 


T4A 




CANAL 2QNE 


14 


7 


7 


7 


7 


7 


14 


14 


14A 


21 


21 


14A 




ENGLAND 


7 


7 


7 


3A 


7 


7 


14 


14A 


14A 


14 


7A 


7 




HAINAN 


14 


7B 


7 


7 


7 


7 


7 


7 


7A 


1 4 


14A 


14A 




INDIA 


7 


7 


?B 


n\ 


7B 


7B 


14 


14 


146 


7B 


7 


7 




JAPAN 


14 


7H 


7B 


IB 


7 


3A 


7 


7 


7 


7 


7B 


14 




MEXICO 


14 


7 


7 


7 


7 


7 


1 


14 


14 










14 A 


14A 


"A 




PHILIPPINES 


14 


7B 


7S 


7B 


7B 


7B 


7 


7 


7 


f 


7B 


7 A 




PUERTO RICO 


7 


7 


7 


7 


7 


7 


7A 


M 


14 


14 


T4 


14 




SOUTH AFRJCA 


7 


? 


7 


7 


7B 


14 


14A 


21 


21 


14A 


14 


14 




U, S. S. R. 


7 


3A 


3A 


? 


7 


7B 


14 


ij 


14 


7A 


7R 


7 




WEST COAST 


14 


7 


7 


7 


7 


7 


7 


14 


14 


14 


14A 


14A 





CENTRAL UNITED STATES 


TO: 


ALASKA 


14 


7A 


7 


7 


3 


3 


3 


7 


7 


14 


14 


14 


ARGENTINA 


14A 


7 


7 


7 


; 


/ 


7 


T4 


21 


21 


21 


21 


AUSTRALIA 


2| 


14 


7B 


7B 


7B 


7B 


7a 


7 


14 


14 


14 


14A 


CANAL Z ONE 


14 


7 


7 


/ 


7 


7 


7 


14 


14A 


21 


21 


14A 


ENGLAND 


7 


7 


3A 


3A 


7 


3A 


7B 


14 


14 


14 


7 


7 


HAWAII 


14 


14 


1 


f 


7 


■' 


7 


7 


7A 


14 


14A 


14A 


INDIA 


7 


7B 


7B 


7B 


78 


3a 


3B 


7 


7A 


7 


7 


7 


JAPAN 


14 


7A 


7B 


7B 


7 


7 


3A 


7 


7 


7 


7B 


1 4 


MEXICO 


H 


7 


7 


7 


7 


7 


7 


14 


14 


14 


14 


14 


PHILIPPINES 


1 4 


7A 


7B 


7B 


7B 


7B 


3A 


7 


7 


7 


7B 


14 


PUERTO RICO 


14 


7 


7 


7 


7 


7 


7A 


14 


14A 


1<1 A 


14A 


14 


SOUTH AFRICA 


14 


7 


7 


7 


7B 


7B 


14 


14A 


21 


14A 


14 


14 


U.S.S. R 


7 


3A 


3 A 


7 


7 


3A 


7B. 


14 


14 


7A 


7H 


7B 


WESTERN UNITED STATES 


TO: 




A - Next nigher frequency may be useful also. 
B = Difficult circuit this period. 



112 



73 MAGAZINE 





MODEL DGA-2M 



SAVOY 



-f+^^^hwb 



Postpaid in U.S.A. 




TYPE 900 A 



TYPE 901 




HIGH ACCURACY CRYSTALS 

FOR OVER 30 YEARS 



2-6-10-15-20 40-75 

Identical size, post, 
and appearance 



Either type for amateur VMF in Regency, Swan, Standard, Drake, Van* 
tronics, Tempo, Yaesu, Galaxy, Trio, Sonar. Clegg, SBE, Genave. 

Quotes on request for amateur or commercial crystals for use in all 
other equipments. 

Specify crystal type, frequency, make of equipment and whether transmit 
or receive when ordering. 



FULLY ADJUSTABLE 
TO FREQUENCY 
IN FIELD 



BASSETT VACUUM BALUN 



$ 



5 ■--'-.* 



■"im 



- t< 



Polished 
chrome brass 

standard 3 /s-24 thread 

High gain collinear 
on 2 meters 







BASSETT VACUUM TRAP ANTENNA SYSTEM 

Complete packaged multi band antenna sys- 
tems employing the famous Bassett Sealed 
Resonators and Balun from which air has 
been removed and replaced with pure 
helium at one atmosphere. Operating bands 
are indicated by model designation. 

MODEL DGA 4075 $59 SO 

MODEL PGA-204075 $79.50 

MODEL DGA 2040 $59.50 

MODEL DGA-T52040 $79.50 



The famous sealed helium filled Balun . . . 
employed with the DGA Series Antenna 
Systems, Solderless center insulator and 
easily handles more than full legal power 
while reducing unwanted coax radiation, 
Equipped with a special SO 239 type coax 
connector and available either 1:1 or 4:1. 

MODEL DGA 2000-B $12.95 

Postpaid in U.S.A. 



CONTACT VOUR DISTRIBUTOR OR WRITE FOR DATA 




- Fart Lauderdale, Florida - 33310 

Tel: 3Q5-56B-8416 or 305-947-1191 



_ 





73 Pine St. 
Peterborough, 
NH 03458 
USA 



\^* 






O tf 











fm 




f two colors 
QSO info book 
10W PRICfg 



Just when you're used to being abused 
by ever skyrocketing prices, 73 comes 
along with yet another way for Hams to 
save money! We have figured out a way 
for you to get High Quality QSL cards 
foraslowasaPENNY-A-PIECEpostpaid! 



These cards are printed on High Quality Glossy Card Stock 
and are as good, or better than cards sold elsewhere for 
two or three times the price. By ganging up QSL printing 
between other jobs in our own print shop, we are able to 
offer you this fantastic low price. At this price, do you 
really have an excuse for not getting in a supply of these 
nice QSLs? Don't be one to give U.S. amateurs a bad name 
by not sending a card when requested. 



(£^ e 



fl 



S STYUS 

to choose from! 




f ORDER 



7J ftme Street 
Prfn-bcfDugh. NH UJWtf 



250 . . 
500 . . 
1000 . 
2000 . 



• » - 



AND PAYy 

. . $6 (2.5dea) 
. . .$10 (2i ea) 
. $15 <1.5dea) 
. . .$20 ( M ea) 




iS^ Ve 



-a 



W 1MSDI I 



• 



Wtynt Grurtl 

73 hrn?Sl'*»! 



P*i*rti»n>iHar.,NH 0345 B 



&SW 



sXvvv. 






ORDER BLANK 



Name 



(First and last name is most friendly) 



Call 






.■:*: 



m 



Address 



(as brief as possible and still get through the mail) 



Style 


1 □ 


2 □ 


3 D 



:-;;:v: 



City. 



State 



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(a must) 



tif desired on the card) 



Awards to be listed on card 



m. 



□ 250 □ 500 □ 1000 □ 2000 cards Amount enclosed $ 







Mail order to: 73 Magazine Peterborough, NH 03458